Category Archives: Tactics

The Strategic Need for Tactical Excellence: Raising the Surface Navy’s Combat Capability

By Rear Adm. Dave Welch

The recent online republication of a 1993 Proceedings article from Capt. Christopher H. Johnson, “The Surface Navy: Still in Search of Tactics,” by the Center for International Maritime Security (CIMSEC) in July 2018 can be interpreted two ways. The reprint either suggests that Capt. Johnson’s cautionary tale of 25 years ago went unheeded and the Surface Forces are substantially unchanged in our approach to the development of tactical proficiency, or it serves as an invitation to examine what has changed.1,2 As the Surface Warfare community prepares to gather for the annual national symposium of the Surface Navy Association, I choose the latter interpretation and offer that there have been significant changes, particularly in the last five years.

In 1993 Capt. Johnson argued that training cycles focused on administrative tasks – a check-in-the-block approach – to build readiness, and that workups lacked a meaningful, deliberate focus on the development of tactical proficiency and expertise in a ship and crew. This critique was not without merit. By 1993 the Cold War had ended, the Soviet Union was dissolved, and the United States Navy enjoyed uncontested access to the open oceans. Focus was shifting to the littorals. Over the next two decades Surface Forces concentrated on power projection and support for the Joint fight ashore, with little impetus to hone our tactical skills in sea control mission sets. That period has ended, however, and the United States Navy is again in the midst of great power competition. Potential adversaries are developing capabilities that challenge our ability to operate in the deep blue, and with that comes an imperative to develop and master tactics that will translate into effective combat power at sea – tactics that take into account the current threats, and developing capabilities of potential adversaries. Fortunately, in contrast to the Surface Navy described by Capt. Johnson, we now have the ways and the means to advance lethality and tactical proficiency in the Surface Navy.  

The establishment of Naval Surface and Mine Warfighting Development Center (SMWDC) in 2015 was a decisive development in our community, perhaps the most important development in a generation.

Lessons Truly Learned

In 1993, Capt. Johnson cast a vision of a Surface Warfare community that provided the latest in advanced tactical training and doctrine and tactics, techniques, and procedures (TTP) to the Fleet to keep it ready, capable, and lethal. Such a vision was not new– it had been developed before in naval aviation. During the Vietnam War, Chief of Naval Operations Adm. Thomas Moorer ordered a commission to examine the precipitous drop in naval fighter squadron combat kill ratios since World War II and the Korean War. The Ault Commission made sweeping recommendations, including the establishment of the Fighter Weapons School (TOPGUN) – a seminal step that took place in March 1969.3 This led to a systemic shift in tactical development and training. Over the following decades this approach expanded to all facets of carrier-based aviation, which now sits as a core mission for the most mature of SMWDC’s counterparts, Naval Aviation Warfighting Development Command (NAWDC).

Critical mass for the expansion of the Fighter Weapons School model into the Navy’s other warfare communities – including Surface Warfare – came in 2014 when Chief of Naval Operations Adm. Jonathan Greenert provided Warfighting Development Centers (WDC) Implementation Guidance to the Fleet.4 This was quickly followed by joint Pacific Fleet and Fleet Forces Commanders’ guidance from Admirals Harris and Gortney that began the internal reorganization of authority and responsibility in the Fleet to achieve the WDC mission.5


SMWDC efforts, including the introduction and growth of a Warfare Tactics Instructor (WTI) program, means that the surface community now moves with purpose to develop tactical expertise. We no longer rely upon personal initiative to cultivate tactical excellence.

SMWDC has grown rapidly since Rear Adm. Jim Kilby took charge as its first commander at the command establishment ceremony in 2015.6 In an early 2016 Proceedings article, he outlined the command’s initial four lines of operations: the development of WTIs, plans for a Surface Warfare Combat Training Continuum (SWCTC), the introduction of Surface Warfare Advanced Tactical Training (SWATT) exercises into the readiness generation cycle, and the standardization and growth of doctrine and TTP led for the community by the command.7 He also laid out plans for three WTI programs in the areas of anti-submarine/surface warfare (ASW/SUW), integrated air and missile defense (IAMD), and amphibious warfare (AMW).

A 2017 Center for International Maritime Security (CIMSEC) article by then-SMWDC Commander Rear Adm. John Wade and his training and operations officer, Capt. Jeff Heames, highlighted the continued growth of the command and also outlined SMWDC’s updated lines of operation: advanced tactical training; doctrine and TTP development; operational support; and capability assessments, experimentation, and future requirements.8 The removal of the WTI program and SWCTC from the updated lines of operation may have surprised the casual observer, but within command lifelines, we clearly understand that WTIs remain the critical enabler to deliver results in these lines of operation.

Today, SMWDC develops WTIs in the three disciplines envisioned. There are currently more than 275 “patch-wearing” Warfare Tactics Instructors, either in production tours to deliver on the four lines of operation, or in post-production tours where they have returned to the Fleet, carrying with them knowledge, expertise, and connections to “WTI Nation.”

VIRGINIA CAPES (Nov. 9, 2018) Lt. Cmdr. Ryan Downing, right, an Anti-Submarine Warfare/Surface Warfare (ASW/SUW) Warfare Tactics Instructor (WTI) from the Naval Surface and Mine Warfighting Development Center (SMWDC), mentors Lt. Cmdr. Kris Yost, the guided-missile cruiser USS Leyte Gulf’s (CG 55) chief engineer (CHENG), during a Fast Attack Craft / Fast Inshore Attack Craft (FAC/FIAC) training event from the ship’s combat information center as part of a Surface Warfare Advanced Tactical Training (SWATT) exercise. U.S. Navy photo by Mass Communication Specialist 3rd Class Jesse Marquez Magallanes/Released)

We have evolved in our shipboard training “reps and sets.” During exercises on both coasts, watch teams are challenged to grow through the use of replay tools that highlight where errors in planning and execution have occurred. While feedback may seem uncomfortable at first, watch teams and warfare commander staffs quickly understand that some of the best lessons come through mistakes, followed by detailed debrief, with opportunities to immediately apply those lessons to rework a plan, rebrief it, then conduct another round of exercises at increased levels of pace and complexity. Watch teams that initially needed the watchful eyes of senior mentors and WTIs to help guide them are operating at such a high level at the end of the exercise that they need little oversight, and begin to hold themselves accountable and teach younger crew members.

Live Fire With a Purpose (LFWAP) is another critical aspect to the Surface community’s advanced tactical training. LFWAP is an enhanced missile exercise program which provides warships the opportunity to develop watch team performance using updated tactics against live, increasingly realistic targets.9   

ATLANTIC OCEAN (Nov. 18, 2018) A Standard Missile 2 (SM-2) is launched from a forward vertical launching system aboard the Arleigh Burke-class guided-missile destroyer USS Mason (DDG 87) during a Live Fire with a Purpose (LFWAP) exercise. (U.S. Navy video by Seaman Nikita M. Custer/released)

Classroom and at-sea training are essential, but the doctrine and TTP required to operate effectively are equally as fundamental to the execution of sea control. SMWDC’s doctrine and TTP teams have reviewed and updated more than 80 tactical publications since 2015. The guiding principles for all SMWDC-reviewed, renewed, and developed doctrine and TTP is that it must be readable, understandable, teachable, and executable. Doctrine and TTP provide warships with the opportunity to read, think, plan, and execute in a more cohesive way.

Ships and afloat staffs can access the latest TTP updates on SMWDC’s collaboration-at-sea account (CAS) webpage, and they can also make inputs to the command’s Tactical Observations Lessons Learned (TOLL) portal. This tool allows the waterfront to provide inputs to SMWDC’s doctrine and TTP branch for consideration and possible implementation into Fleet-wide publications.

Surface Force Life Blood

The cultural shifts represented by SMWDC are rooted in talent accession, training, and development as Warriors, Thinkers, and Teachers, embodied within the Warfare Tactics Instructor (WTI) cadre. SMWDC’s development as a driving force behind a culture of excellence within the Surface Fleet will ensure that the deliberate development of tactical expertise flourishes in the Navy.

The value of the WTI is not solely within the individual. It is in the character traits that are emphasized to WTI candidates: humility, credibility, and approachability. These are carried through SMWDC’s day-to-day lines of operation, the training that WTIs provide in production tours, and the continued influence they have when they return to the Fleet.

Admiral Christopher Grady, Commander, U.S. Fleet Forces, highlighted the significant impact that SMWDC and WTIs have already made in their early years of existence:

“SMWDC continues to drive a rapid and sustainable increase in the warfighting proficiency and capability of the Surface Fleet and our Navy as a whole. There is an insatiable appetite in the Fleet for the training, TTP and doctrine updates, and direct operational support this team provides reliably in all fleet concentration areas. In just a few short years, SMWDC has become the place to be in the Surface Navy when it comes to the profession of arms in the maritime domain.(emphasis added)10

The two most recent Commander Command Screening Board results are reflective of his remarks. On the FY19 board, ten WTIs were eligible on their first-look and six were selected (60 percent). Nine officers were eligible for their second-look on that board, and all screened for a milestone tour – three XO/CO, four XO Afloat, and two XO special mission. On the recently released FY20 board, 19 of 23 WTIs were selected (82.6 percent) for milestone tours and 8 of 11 WTI-selects screened for a milestone. For any program – especially a young one – these are outstanding numbers.


SMWDC’s vision is to mature into an elite (not elitist) organization that continues to learn while accomplishing our mission with enthusiasm and innovation. We strive to maintain humble attitudes as we approach each event, exercise, or engagement within our mission set. SMWDC’s maturation continues as this critical return on investment is realized throughout the Fleet.

The WTI program will expand in 2019 to include a Mine Warfare (MIW) WTI program.11 Similar in design to the other three WTI programs, MIW WTIs will attend the WTI baseline course at SMWDC headquarters, but will continue training at Ecole de Guerre des Mines (EGUERMIN), otherwise known as the NATO Naval Mine Warfare Centre of Excellence in Belgium. The first MIW WTIs will then play a leading role in the development of a group of naval professionals who are steeped in mine warfare tactics.

As growth continues, it means that difficult decisions must be made to ensure that we effectively manage our talented SMWDC enablers and WTIs. The command works closely with the team at PERS-41 to develop strategies to recruit top talent, and to seek professional development opportunities for WTIs, including some of the Fleet’s most prestigious programs. Many WTIs are completing coursework through the Naval Postgraduate School, and recently an ASW/SUW WTI was selected for the Fleet Scholars Education Program and will attend the Massachusetts Institute of Technology (MIT).

Charting a New Course

In closing, I would like to return to Capt. Johnson’s article, and offer an alternative vignette that demonstrates where we are today – a construct that offers great value to current readiness generation processes, with great potential for continued improvement.  


Two weeks into the warship’s post-deployment stand down the captain of the guided missile cruiser – having just complete a full deployment as “Whiskey” – quietly took a moment to reflect on his team’s progress over the last two years as a ship and warfare commander team. He was already thinking about how his team would approach their next training cycle, and what improvements needed to occur.  

The deployment had been challenging, but also richly satisfying from Day One. The captain remembered what he felt like pulling away from the pier, knowing that his ship and Strike Group team had completed a training process that left him and his crew knowledgeable of the threats they faced, and confident in their procedures and tactics. It was a good feeling to know that he and the ship were prepared – in fact, more tactically astute than any ship he previously served aboard in in his career.

After completing all basic phase certification requirements, the strike group warships and warfare commanders completed Surface Warfare Advanced Tactical Training (SWATT) – a period of in-port academics to review current tactics, techniques, and procedures in detail, directly followed by an at-sea period in which he and his teams stepped through those TTP – all under the watchful eye of WTIs. They did their reps and sets, followed by a debrief… always a debrief… in which the WTIs highlighted good performance and objectively pointed out missed steps, mistakes, or just items that needed more attention. They launched weapons in an enhanced missile exercise program called LFWAP, against realistic and challenging targets. They weren’t simply complying with regulations – they learned to drive excellence within their teams and across the ship by breaking down traditional barriers often raised by ego and pride.

He learned that the advanced training he and his team experienced in 2017-18 enabled a higher level of combat readiness.12 But he also knew that his ship operated in an era in which improvement must continue.

The United States Navy was once again in a competition – a competition for sea control.

At that moment Chief Warrant Officer Troy Woods and Lt. Cesar Mize, IAMD and ASW/SUW WTIs respectively, walked into his cabin to discuss their training plan and combat system modernization. Capt. Joe Cahill’s apprehension faded as he listened to these two young officers with expertise steeled by experience lay out a plan for raising the combat capability of the warship and the warfare commander assets under their charge.

The captain smiled at his shipmates, and listened carefully to their observations and recommendations.


We still have much work to do to develop the talent, write the tactics, train our crews, and field the tools that will enable the Surface Force to continue to control the sea and project power. But I am confident we are on the right path. What remains is to execute the plan, hold the line, and own the fight. Let’s get to work.

Rear Admiral Dave Welch is the third commander of Naval Surface and Mine Warfighting Development Center (SMWDC).


1. Johnson, C. H. (1993, November 9). The Surface Navy: Still in Search of Tactics. Retrieved from

2. Johnson, C. H. (2018, July 11). The Surface Navy: Still in Search of Tactics. Retrieved from

3. Ault, F. W. (1968). Report of the Air to Air Missile System Capability Review (pp. 1-58, Issue brief). Naval Air Systems Command. Retrieved from

4. United States of America, Department of the Navy, Chief of Naval Operations. (2014). Warfighting Development Centers Implementation Guidance (N00/100078, pp. 1-5).

5. United States of America, Department of the Navy, United States Fleet Forces Command / United States Pacific Fleet. (2014). Warfighting Development Centers (COMUSFLTFORCOM/COMPACFLTINST 3501.4, pp. 1-26).

6. Ingle, D. M. (2014, June). Official U.S. Navy website – Commander Naval Surface Force, U.S. Pacific Fleet. Retrieved from

7. Kilby, J. (2016, January). USNI. Retrieved from

8. Wade, J., & Heames, J. (2018, February 04). Warfare Tactics Instructor: A Unique Opportunity for Junior Officers. Retrieved from

9. Naval Surface and Mine Warfighting Development Center. (2018, August 08). Home Page. Retrieved from

10. Naval Surface and Mine Warfighting Development Center. (2018, June 27). Home Page. Retrieved from

11. Naval Surface and Mine Warfighting Development Center. (2018, September 14). Home Page. Retrieved from

12. Eckstein, M. (2018, March 29). Deployed Surface Forces Benefitting from SMWDC Training, Technologies. Retrieved from

Featured Image: 170310-N-FV739-154 WATERS SOUTH OF JAPAN (March 10, 2017) Ships participating in MultiSail17 sail in formation during a photo exercise (PHOTOEX). (U.S. Navy photo by Mass Communication Specialist 3rd Class Christopher A. Veloicaza/Released)

On the Cutting Edge of U.S. Navy Exercising: Surface Warfare Advanced Tactical Training

By Dmitry Filipoff

CIMSEC had the opportunity to ask leaders at the Naval Surface and Mine Warfighting Development Center (SMWDC) and the USS Abraham Lincoln (CVN 72) Carrier Strike Group about the first East Coast Carrier Strike Group (CSG) Cruiser-Destroyer (CRUDES) Surface Warfare Advanced Tactical Training (SWATT) exercise. This SWATT exercise involved the Norfolk-based Arleigh Burke-class guided-missile destroyers USS Gonzalez (DDG-66), USS Mason (DDG-87), USS Bainbridge (DDG-96), USS Gravely (DDG-107), and USS Nitze (DDG-94), as well as the Ticonderoga-class guided-missile cruiser USS Leyte Gulf (CG-55).

CRUDES SWATT exercises are unique in that they provide a dedicated advanced tactical training period for surface combatants and their crews to focus on sea control and maritime warfare before integrating with other elements of the strike group. 

Live Fire With a Purpose (LFWAP) exercises took place during the same time period. SMWDC is Commander, U.S. Fleet Forces Command and Commander, U.S. Pacific Fleet’s executive agent for the LFWAP program. Commander, USS Abraham Lincoln (CVN 72) Carrier Strike Group, provided leadership of LFWAP execution in real-time. 

Primary respondents include both trainers and the training audience, including CAPT Joe Cahill (JC), Division Director of SMWDC’s Sea Combat Division, and CAPT Grady Musser (GM), commanding officer of USS Leyte Gulf (CG 55). Collaborators include CAPT Paul Hogue, prospective Division Director of SMWDC Integrated Air and Missile Defense Division, and CAPT Sean Anderson, commodore of Destroyer Squadron (DESRON) 2.

The Trainers

Could you describe the structure of the event as far as what happens in those several weeks?

JC: SWATT provides warships and warfare commanders advanced tactical training at sea designed to raise the combat capability they provide the nation as integrated elements of a Naval Task Group. SWATT builds on the work those warships and warfare commanders conduct during the basic phase portion of the combat readiness generation cycle and positions them to move into the final phases of training prior to deployment.

Specifically, SWATT provides a crawl-walk-run approach to advanced tactical training in Integrated Air & Missile Defense (IAMD), Anti-Surface Warfare (ASuW), Anti-Submarine Warfare (ASW), Amphibious Warfare (AMW), Mine Warfare (MIW), and Information Warfare (IW). SWATT exercises include in-port academics followed by underway training. Underway training scenarios culminate in live fire exercises based on current threats from the 5th, 6th, and 7th Fleets.

A critical element of SWATT, which can include both Carrier Strike Group (CSG) Cruiser-Destroyer (CRUDES) and Amphibious Ready Group (ARG) constructs, includes teaching the plan, brief, execute, debrief (PBED) process. Embarked SMWDC senior mentors and Warfare Tactics Instructors (WTI) work closely with shipboard leaders and teams, as well as members of the technical community, to create an enhanced learning environment where true learning and team growth can take place.

First, the teams develop plans for each of the events throughout the exercise for the training audience. Second, the training audience teams work together to brief the plan to their teams before executing the event, and to ensure that the manning, resources, and capabilities are in place to execute the event as planned. After that is complete, the team executes the event with SMWDC senior mentors and WTIs actively engaged in mentorship of the training audience during the exercise. At the end of each event, the teams leverage the talent and expertise of the technical community to reconstruct the days’ events, creating a “replay” of the day that enables a review of the team’s performance, and to determine where improvement can be made in the next training event of the exercise.

November 18, 2018 — The Arleigh Burke-class guided-missile destroyer USS Mason (DDG 87) launches a Standard Missile 2 during a Live Fire With a Purpose (LFWAP) event. (U.S. Navy video by Mass Communication Specialist 3rd Class Jesse Marquez Magallanes/Released)

While teams are initially reticent to participate in this process because it takes a significant upfront investment in time, this changes as they go through the PBED experience. The investment of time to plan and to debrief requires a significant behavioral shift at both the warship and warfare commander levels. However, as the warfighters experience improved combat performance they become actively engaged in the process, grow a great deal, and leave SWATT with an ability to be much more objective about their own performances. This objectivity leads to higher levels of combat power and increases the commander’s ability to measure the degradation of combat power over time. This is exactly what the strategic environment mandates for us to face our competitors.

How do the scenarios become progressively more complex throughout the event, and how much of the training could be described as mostly free-play and open-ended?

JC: The events become more challenging throughout the exercise, and it is inspiring to watch the growth of teams throughout. The key is for leadership at all levels to be engaged throughout the process from the warfare commander on down to the lowest levels. These are the teams we see make the greatest gains throughout training. SWATT exercises are an essential element of our ability to turn readiness and capability into combat power.

Does SWATT take the form of a certification event or is it different in nature?

JC: This is a great question! Warships that participate in SWATT have basic requirements they need to meet in order participate in SWATT. However, SWATT is not a certification event. It is a learning and training environment for warfare commanders and warships. While we implement the planning, briefing, executing, and debriefing processes, humility and team growth is at the center of the exercise. We cannot grow if we aren’t hard on ourselves, and removing a “certification” element to the exercise allows us to best achieve the highest levels of learning.

How do you handle failure, and how is the learning experience different for a crew that fails versus one that succeeds?

JC: It is important that we take the word failure out of the mix when we talk about SWATT.

The way we handle growth, errors, and misjudgment in SWATT is with honesty and humility. Humility is the touchstone of growth in the process, and if we cannot be honest with ourselves in a training environment, then we certainly aren’t going to be honest with ourselves and our performance in theater during routine operations or in a combat scenario. It’s a bit cliché, but we don’t rise to our aspirations in war – we fall to our lowest levels of training. That’s why we do SWATT.

From SMWDC’s perspective, the difference between teams that learn and grow to their maximum potential during SWATT are those that are totally engaged and those that simply go through the paces. It’s fairly straightforward – those that take it seriously learn and grow as warfighters. Those that don’t will still learn, but just not as much.

The tremendous value in this is that teams and leaders who learn to be truly humble through this process, and those that take advantage of the learning tools that we provide, do become self-starters when it comes to learning. That is the goal of this process. We also see similar results on ships that have Warfare Tactics Instructors (WTI) as part of their teams when they complete their production tours. They harness the value of the principle and process and move out with a purpose.

Is there a way for Sailors to view the results of previous SWATT exercises and learn from the experiences of other Sailors? 

JC: Absolutely. Before SWATTs, our planners work with the teams that will be the next participants to bring them up to speed on observations on the most recent SWATTs to help them optimize the training experience.

Further, there is an opportunity for the Fleet to stay engaged by staying up to date with the latest doctrine and tactics, techniques, and procedures (TTP) through the SMWDC online collaboration portal. Additionally, they can stay engaged by providing observations and lessons learned from their own experiences into the Tactical Observations Lessons Learned (TOLL) portal which provides a venue for the Fleet to ensure that what is happening at the tactical level enters the broader Surface Fleet’s consciousness and future iterations of TTP.

How can the training audience remain connected to tactical development and continue to follow what SMWDC is doing?

JC: I encourage surface warfare junior officers to learn about the Warfare Tactics Instructor (WTI) program and apply. WTIs are tactical subject matter experts and increase the proficiency, lethality, and warfighting capabilities of the Surface Force.

By becoming a WTI they earn greater-than-normal tactical classroom training followed by a production tour where they support SMWDC’s lines of operation – including advanced tactical training – throughout the Fleet. Additionally, they become a part of the cadre of WTIs that comes together once a year for a Re-Blue event where they re-baseline tactical expertise within their specific warfare area – Anti-Submarine Warfare/Surface Warfare (ASW/SUW), Amphibious Warfare (AMW), Integrated Air and Missile Defense (IAMD), or Mine Warfare (MIW).

This is by far the most effective way to stay actively engaged in the process. Of course, keeping an eye on message traffic, tactical bulletins, tactical memoranda, and other warfighting updates is an excellent way to stay up-to-date, though becoming a WTI is the number one choice for tactically-minded junior officers who want to be tactically engaged and strategically relevant.

The Training Audience 

What was it like to go head-to-head against other ships in the more complex, multi-mission area scenarios?

GM: Having SWATT built into the schedule is a perfect opportunity for us to come together as warship COs and warfare commanders to develop our unit and warfare area expertise and tactical proficiency. This process is similar in some ways to what the aviation community does in Fallon during their training cycle, and we’re excited to have a similar opportunity.

It is also very helpful to have a command that is dedicated to warfighting development in the Surface Community, and that provides alignment regardless of where Fleet ships operate. While our assigned mission sets may be different when we chop into theater, the tactical skills needed by each ship to execute effectively in a contested environment don’t change too much. It’s all about how you use those tactics to your competitive advantage.

VIRGINIA CAPES (Nov. 8, 2018) Capt. William G. Musser, commanding officer of the guided-missile cruiser USS Leyte Gulf (CG 55), addresses his crew on their performance during an all-hands call on the ship’s flight deck while the Leyte Gulf completes a Surface Warfare Advanced Tactical Training (SWATT) exercise. (U.S. Navy photo by Mass Communication Specialist 3rd Class Jesse Marquez Magallanes/Released)

What was it like to go through the WTI-led Plan, Brief, Execute, Debrief (PBED) process, and how is this an evolution in reflecting on a training experience?

GM: There hasn’t been anything specifically like this in our community since I’ve been in, and to see how far we’ve come since the WDCs were established a few years ago is really incredible. The support of the technical community and their integration with SMWDC to ensure that we have rapid, ground truth feedback is exceptional, and allows our teams to learn and grow rapidly.

Let’s be honest. Nobody likes to do something wrong. And certainly, nobody likes to be told that they could do something better. But what we do like is being good warfighters and an important part of our nation’s defense and warfighting team. Unfortunately, you can’t do one without the other. You absolutely have to eat your vegetables, you have to do your homework, and you have to do your pushups. That’s what SWATT is. It isn’t about getting it perfect, it’s about learning.

As a leader, that’s perhaps my biggest challenge, to get my team ready and in the mindset that this isn’t a test – we’re here to make mistakes and grow. That isn’t always the case when we do certifications and other events, but it’s a critical leadership challenge for ship COs to sort through.

I’m very proud of our team and what we’ve accomplished, and I know we’re a more valuable asset to our Strike Group Commander today than we were before we completed SWATT. 

As far as training goes, what is something you think the crews will be able to do better on their own after experiencing SWATT and receiving tailored instruction from the WTIs?

GM: All of us have to learn how to learn. It isn’t an easy thing to do, and when you’re a professional, it can be easy to trick yourself into thinking that you have the market cornered on smarts. The truth is that we have to continue to learn throughout our careers if we hope to stay ahead of our strategic competitors.

The team that came aboard was impressive, knowledgeable, and helpful. My team learned a great deal about each of the warfighting areas trained on during SWATT. They also learned about ways that they can access training and support to continue to sharpen their tools and provide feedback to the enterprise after SWATT. There’s no doubt that this was a great opportunity for my team to learn and grow as warfighters.

After going through SWATT and learning about potential areas that have room for improvement, what will you do to continue to improve the tactical proficiency of the crew going forward?

GM: Keeping our team engaged in tactical development through drills, advanced training schools for our teammates, and staying engaged with the WDCs through providing feedback and staying up-to-date with doctrine and TTP updates are critical ways that we can keep growing.

Thank you.

Capt. Cahill is currently the director of SMWDC Sea Combat Division. At sea he has commanded USS MONSOON (PC 4), USS PREBLE (DDG 88) and USS BUNKER HILL (CG 52). Ashore he has served on a number of COCOM and OPVAV Staffs.

Capt. Musser is a career Surface Warfare Officer who has served in a cruiser and multiple destroyers. A former commanding officer of USS Farragut (DDG 99), he is the commanding officer of USS Leyte Gulf (CG 55). He is a 1996 graduate of the U.S. Naval Academy and graduated with distinction from the Naval Postgraduate School with a Master’s degree in National Security Affairs.

Dmitry Filipoff is CIMSEC’s Director of Online Content. Contact him at

Featured Image: WATERS OFF THE KOREAN PENINSULA (Oct. 11, 2018) The Ticonderoga-class guided-missile cruiser USS Chancellorsville (CG 62), front, steams alongside the Nimitz-class aircraft carrier USS Ronald Reagan (CVN 76) during a pass-in-review as part of the Republic of Korea navy to help enhance mutual trust and confidence with navies from around the world. (U.S. Navy photo by Mass Communication Specialist 2nd Class Elesia Patten)

Sea Control Through The Eyes of the Person Who Does It, Pt. 2

The following article originally appeared in The Naval War College Review and is republished with permission. Read it in its original form here. It will be republished in three parts, read Part One here

By Christofer Waldenström 

The Field of Sensors

To determine whether the field of safe travel is receding toward the minimum safety zone, the commander must be able to observe the objects present in the naval battlefield. Today, the naval battlefield comprises more than just the surface of the sea. Threats of all sorts can come from either beneath the surface or above it. The driver of a car determines from the pertinent visual field whether the field of safe travel is receding toward the minimum stopping zone.22 For a commander, however, it is not possible to perceive directly the elements of the operations area—the naval battlefields are far too vast. Instead, as noted above, the objects present have to be inferred, on the basis of sensor data.23

Thus, there exists a “field of sensors” that the commander uses to establish whether the field of safe travel approaches the edge of the minimum safety zone. The field of sensors is an objective spatial field the boundaries of which are determined by the union of the coverage of all sensors that provide data to the commander. The importance of the sensor field is also emphasized in one theory of perception-based tactics that has been advanced (though without discussion of its spatial dimensions).24 As the sensors that build up the field have different capabilities to detect and classify objects, the field of sensors will consequently consist of regions in which objects can be, variously, detected and classified with varying reliability. (These regions could be seen as fields in their own right, but for now we will leave them as is.) Nevertheless, to establish the boundary of the field of safe travel and determine whether it is receding toward the minimum safety zone, the commander must organize the field of sensors in such way that it is possible both to detect contacts and to classify them as nonhostile before they get inside the minimum safety zone.

Factors Limiting Detection

Several factors limit the detection of enemy units. First, terrain features can provide cover. Units that hide close to islands are difficult to detect with radar. In a similar way, a submarine that lies quietly on the bottom is difficult to distinguish from a rock formation with sonar. The weather is another factor: high waves make small targets difficult to detect; fog and rain reduce visibility for several sensors, such as visual, infrared, and radar; and temperature differences between layers in the atmosphere and in the water column influence how far sensors can see or hear. Yet another factor is stealth, or camouflage, whereby units are purposely designed to be difficult to detect with sensors. Sharp edges on a ship’s hull reflect radar waves in such ways that they do not return to the transmitting radar in detectable strength. Units are painted to blend into the background, propulsion systems are made silent, ships’ magnetic fields are neutralized, and exhaust gases are cooled—all to reduce the risk of detection. Being aware of these factors makes it possible for commanders to use them to advantage. Units might be positioned close to islands while protecting the field of safe travel, or the high-value units might select a route that will force the enemy units to move out at sea, thus making themselves possible to detect.

Factors Limiting Classification

To avoid being classified, the basic rule is to not emit signals that allow the enemy to distinguish a unit from other contacts around it. Often naval operations are conducted in areas where neutral or civilian vessels are present, and this makes it difficult to tell which contacts are hostile. To complicate matters, the enemy can take advantage of this. For example, an enemy unit can move in radar silence in normal shipping lanes and mimic the behavior of merchants, so as to be difficult to detect using radar and electronic support measures. Suppressing emissions, however, only works until the unit comes inside the range where the force commander would expect electronic support measures to classify its radar—no merchant ever travels radar silent. To detect potential threats the commander establishes a “picture” of the normal activities in the operations area. Behavior that deviates from the normal picture is suspect and will be monitored more closely. Thus, contacts that behave as other contacts do will be more difficult to classify.

The Field of Weapons

As mentioned above, the commander has three choices for handling a detected threat: move the high-value units away from the threat, take action to eliminate the threat, or receive the attack and defend. In the two latter cases the threat can be eliminated either by disabling it or by forcing it to retreat. Either way, the commander must have a weapon that can reach the target with the capability to harm it sufficiently. It is immaterial what type of weapon it is or from where it is launched, as long as it reaches the target and harms it sufficiently. Thus, the weapons carried by the commander’s subordinate units, or any other unit from which the commander can request fire support, create a “field of weapons” in which targets can be engaged. Like the field of sensors, the field of weapons is a spatial field, bounded by the union of the maximum weapon ranges carried by all units at the commander’s disposal. The field of weapons is further built up by the variety of weapons, which means that the field consists of different regions capable of handling different targets. For example, there will be regions capable of engaging large surface ships, regions capable of destroying antiship missiles, and other regions capable of handling submarines. Nevertheless, to prevent the high-value units from being sunk, the field of weapons must be organized in such way that it is possible to take action against hostile units and missiles before they get inside their corresponding minimum safety zones. For example, the threat posed by air-to-surface missiles can be dealt with by protecting two minimum safety zones. The commander can take out the enemy aircraft before they get a chance to launch the missile—that is, shoot down the aircraft before they enter the minimum safety zone created by the range of the missile they carry. If this fails the commander can take down the missiles before they hit the high-value units—that is, shoot down the missiles before they get inside the minimum safety zone created by the distance at which the missile can do damage to the high-value units.

It is now possible to specify how the fields of sensors and weapons work together: the field of sensors and the field of weapons must be organized in such a way that for each field of safe travel hostile units can be detected, classified, and neutralized before they enter the corresponding minimum safety zone. One scholar of naval tactics and scouting touches on what can serve as an illustration. Closest to the ships that should be protected is a zone of control where all enemies must be destroyed; outside the zone of control is a zone of influence or competition, something like a no-man’s-land.25 Outside the zone of influence is a zone of interest where one must be prepared against a detected enemy. Scouting in the first region seeks to target; in the second, to track; and in the third, to detect. Important to notice is that the field of sensors and the field of weapons are carried by, tied to, the commander’s units, which simultaneously bring the fields to bear with respect to all pairs of fields of safe travel and minimum safety zones. This complicates matters for the commander. As the fields of safe travel and minimum safety zones are stacked, actions taken to tackle a threat to one minimum safety zone may create problems for another. The competition of units between the pairs of minimum safety zones and fields of safe travel may lead to a situation where a managed air-warfare problem creates a subsurface problem. This bedevilment is not unknown to the naval warfare community: “The tactical commander is not playing three games of simultaneous chess; he is playing one game on three boards with pieces that may jump from one board to another.”26

To illustrate the problem, suppose that the situations in figure 3 occur simultaneously; there is both a surface and a subsurface threat to the high-value unit. In this case the field of sensors has to be organized so that contacts can be detected and classified in a circular field with a radius of a hundred kilometers (for the antiship missile, figure 3a) and also within a smaller and elliptical field (figure 3b, in the torpedo case). For example, radars and electronic support measures have to be deployed to detect and identify surface contacts, while sonar and magneticanomaly detection have to be used to secure the subsurface field. Accordingly, the field of weapons has to be organized so that contacts can be engaged before entering the respective minimum safety zones—antisubmarine weapons for subsurface threats and antiship weapons for surface threats.

Not only weapons can be used to shape the field of safe travel; another means to influence it is deception. Deception takes advantage of the inertia inherent in naval warfare. First, there is the physical inertia whereby a successful deception draws enemy forces away from an area, giving an opportunity to act in that area before the enemy can move back. Second, there is the cognitive inertia of the enemy commander. It takes some time before the deception is detected, which gives further time. Deception can, thus, be seen as a deliberate action within the enemy’s field of sensors to shape the field of safe travel to one’s own advantage. For successful deception it is necessary that commanders understand how their own actions will be picked up by the enemy’s field of sensors and that they be aware of both the enemy’s cognitive and physical inertia. The commander has to “play up” a plausible scenario in the enemy’s field of sensors and then give the enemy commander time to decide that action is needed to counter that scenario (cognitive inertia) and then further time to allow the enemy units to move in the wrong direction (physical inertia). The central role of inertia will be further discussed later.

Having defined the fundamental fields it is now possible to formulate what is required from commanders to establish sea control. The skill of securing control at sea consists largely in organizing a requisite set of pairs of correctly bounded minimum safety zones and corresponding fields of safe travel shaped to counter actual and potential threats, and in organizing the field of sensors and field of weapons in such way that that for each field of safe travel, hostile contacts can be detected, classified, and neutralized before they enter the corresponding minimum safety zone.

Factors Limiting the Field of Safe Travel

So far it has been said that it is the enemy that limits and shapes the field of safe travel. This is, however, not the whole truth. The field of safe travel is also shaped by other physical and psychological factors.

Terrain Features That Reduce Capability to Detect and Engage Targets

To be able to sink the high-value unit the enemy must detect, classify, and fire a weapon against it. All this must happen in rapid succession, or the high-value unit may slip out of the weapon’s kill zone. This means that to fire a weapon against the high-value unit the enemy must organize its field of sensors and its field of weapons so that they overlap the high-value unit at the time of weapon release. In this way the field of safe travel is built up by all the paths that take the high-value unit outside the intersection of the enemy’s field of sensors and the enemy’s field of weapons. This further means that the boundaries of the field of safe travel are determined in part by terrain regions where high-value units can go but enemy weapons cannot engage them—for example, an archipelago that provides protection against radar-guided missiles. The boundaries are also determined by the enemy’s capability to detect the high-value units, and thus terrain features can also delimit the field of safe travel in that they protect the high-value units from detection. For example, the archipelago mentioned above also provides protection against detection by helicopter-borne radar, as long as the ships move slowly. (If they start to move quickly, however, they will stand out from the clutter of islands.) It is also important to notice that a minimum safety zone is resized in the same way as the corresponding field of safe travel—if the enemy cannot see the high-value unit or has no weapon that can engage it, the enemy unit can be allowed closer in.

Terrain Regions Where Enemy Units Can Hide

Like enemy units, potential threats also throw out lines of clearance. One such potential threat is a terrain feature where the enemy might have concealed units and from which attacks can be launched (see figure 4a). Such regions—for example, islands where enemy units can hide close to land—contain potential threats. There may or may not be actual threats there, the objective field of safe travel may or may not be clear, but since commanders can only react to their subjective fields, the latter are properly shaped and limited by these barriers.

Terrain features that serve as good attack points for the enemy also radiate lines of clearance, and they shape the field of safe travel (a); enemy units may or may not be present. In (b) the field of safe travel is impinged by the potential location of enemy units. When an enemy unit slips out of the field of sensors, it creates an area of potential threat that grows as time passes. These potential threat areas also determine the boundaries of the commander’s subjective field, although here the enemy never encroached on the objective field and is now well clear of it.

Enemy Units That Are Spotted and Then Lost

Another potential threat that will radiate clearance lines arises from the movement of enemy units. It is possible for a contact that has been detected and classified to slip out of the field of sensors —for instance, by turning off its radar after being tracked by electronic support measures. The potential movement of such a unit shapes the field of safe travel. Suppose an enemy unit was detected at position p at time t (see figure 4b). As the enemy is outside the field of safe travel, it does not pose a threat to the commander at this time. Now, the contact slips out of the field of sensors, and contact with it is lost. As time passes and the commander fails to reestablish contact, the region where the unit can be is a circle that grows proportionally to the maximum speed of the enemy unit. Eventually the region grows to such a size that it is not possible for the force to pass without the minimum safety zone intersecting with it. In figure 4b the subjective field of safe travel is correctly shaped by the potential threat, but the objective field of safe travel is clear—the enemy unit has turned around and is heading away.

Legal Obstacles and Taboos

 The field of safe travel is also limited by international law. One such legal obstacle is the sea territory of neutral states. A neutral state has declared itself outside the conflict the commander is involved in, and this prohibits the parties of the conflict from using its sea territory for purposes of warfare. Such regions delimit the fields of safe travel and thus restrict where the commander’s units can move. On the other hand, they do not pose a threat to the high-value units and can safely be allowed to encroach on the minimum safety zone.

Neutral Units in the Operations Area

Today, as noted, naval operations take place in areas where neutral shipping is present. Like the sea territory of neutral states, neutral shipping is protected by international law. A consequence of this is that neutral shipping in the area also influences the shape of the field of safe travel. The commander is of course prohibited from attacking neutral merchants. This is not a problem in itself—if a certain contact is classified as neutral, we cannot engage it. Nevertheless, it has implications for where high-value units are allowed to move. As neutral shipping cannot be engaged, we are forbidden to use it for cover—for instance, to move so close to a merchant vessel as to make it difficult for the opponent to engage without risk of sinking the merchant. This means that neutral shipping creates “holes” in the field, where combatants are not allowed to move. If the commander does not track the merchant vessels continuously, these holes grow proportionally to the merchants’ maximum speed, as they do for enemy units spotted and then lost.


Mines shape the field in the same way that ships do. They can be seen as stationary ships with limited weapon ranges; the minimum safety zone for a mine would be the range at which a ship could pass it without being damaged if the mine detonated. Laying mines shapes the commander’s field, and the commander must react, either by taking another route or by actively reshaping the field—that is, by clearing the mines. Clearing mines has the same effect as taking out enemy ships; the field of safe travel expands into the area that has been cleared. Of course, the enemy can use this for purposes of deception, pretending to lay mines, sending a unit zigzagging through a strait, and making sure that the commander’s field of sensors picks this up. If the deception is successful, the commander’s subjective field is shaped incorrectly.

Dr. Waldenström works at the Institution of War Studies at the Swedish National Defence College. He is an officer in the Swedish Navy and holds an MSc in computer science and a PhD in computer and systems sciences. His dissertation focused on human factors in command and control and investigated a support system for naval warfare tasks. Currently he is working as lead scientist at the school’s war-gaming section, and his research focuses on learning aspects of war games.


22. Gibson and Crooks, “Theoretical FieldAnalysis of Automobile-Driving,” p. 457.

23. Intelligence reports from higher command are also included when constructing this operational view of the battlefield. This operational view of the battlefield is compiled by exchanging and merging sensor data, a partly manual and partly automatic process well known in all navies. The result is usually displayed as a map of the operations area overlaid with symbols representing the objects present in varying stages of classification— detected, classified, or identified.

24. T. Taylor, “A Basis for Tactical Thought,” U.S. Naval Institute Proceedings (June 1982).

25. Hughes, Fleet Tactics and Coastal Combat.

26. Ibid., p. 196.

Featured Image: MEDITERRANEAN SEA (July 25, 2012) A plane captain signals to the pilot of an F/A-18C Hornet assigned to the Blue Blasters of Strike Fighter Squadron (VFA) 34 on the flight deck of the Nimitz-class aircraft carrier USS Abraham Lincoln (CVN 72). (U.S. Navy photo by Mass Communication Specialist Seaman Joshua E. Walters/Released)

Sea Control Through The Eyes of the Person Who Does It, Pt. 1

The following article originally appeared in The Naval War College Review and is republished with permission. It will be republished in three parts. Read it in its original form here.

By Christofer Waldenström 

This article suggests a new perspective on the old problem of protecting ships at sea, for two reasons. First, although screen tactics and other defensive measures have been developed and used for many years, this new perspective will be useful in addressing two developments since the late nineteenth century: attackers are no longer just other ships but also aircraft, submarines, and, recently, missiles with very long ranges launched from the land; also, torpedo boats, coastal submarines, and mines have complicated operations in congested and archipelagic waters. The second reason for a new approach is that in order to support commanders in the problems of sea control we need to study the issues they encounter while solving them. This requires a description of each task that commanders have to do; without such a description it becomes difficult to determine which actions lead to increased control and which to loss of control, which in turn makes it harder to identify whether commanders are running into trouble and if so, why. The new analytical method introduced here represents an attempt at such a description. As such, it may enrich and extend traditional thinking about sea control and how to achieve it, especially in littoral waters.

Sea control is generally associated with the protection of shipping, and it refers normally either to a stationary patch of water, such as a strait, or to a region around a moving formation of ships. Today it is quite well understood how to protect such a region of water. To handle aircraft and missiles, defenses are organized in several layers, with an outer layer of combat air patrols to take out enemy aircraft before they can launch their weapons. Next is a zone where long- and short-range surface-to-air missiles take down missiles that the enemy manages to fire. Any “leakers” are to be handled by soft-kill and hardkill point defenses—for example, jammers, chaff, and close-in weapon systems. For submarines and surface vessels the logic is similar, but here maneuver is also an option. Since the attacking surface ship or submarine moves at about the same speed as the formation, it is possible to stay out of reach of the enemy. Maneuver seeks to deny detection and targeting and to force attacking surface ships and submarines to operate in ways in which they cannot muster enough strength to carry out their mission or are more easily detected.1

A prerequisite of a successful layered defense is detection of the enemy far enough out that all the layers get a chance to work. The restricted space of congested and archipelagic waters, however, may prevent the outer “strainers” from acting on the enemy. This gives small, heavily armed combatants opportunities to hide, perhaps among islands, and fire their weapons from cover, leaving only point defenses to deal with the oncoming missiles and torpedoes, with little room for maneuver.2 This increases the risk of saturation of defense systems and may allow weapons to penetrate.

The problems associated with archipelagic and coastal environments have been recognized since the introduction of the mobile torpedo.3 The torpedo gave small units the firepower to destroy ships much larger than themselves and made it possible for a small fleet to challenge a larger one, at least if it did not have to do so on the open ocean. To deal with such an inshore threat, the British naval historian and strategist Sir Julian Corbett suggested in 1911 that a “flotilla” of small combatants had to be introduced to deal with this type of warfare, because capital ships could no longer approach defended coasts, as they had when ships of the line dueled with forts.4 Today, the introduction of long-range missiles, mines, stealth design, and the ability to coordinate the efforts of land-, sea-, and air-based systems have further intensified this threat.5

Littoral environments seem to change the problem of sea control, at least in some aspects.6 Sensors, weapons, and tactics developed to handle threats on the open ocean may be less appropriate in congested and archipelagic waters. Radar and sonar returns are cluttered, missile seekers are confused, and targeting is complicated by the existence of islands and coastlines close to the ships to be protected. The land-sea environment introduces variables that make the sea control problem hard to solve using methods developed for an open ocean. As the uncertainties and intangibles mount up, quantitative approaches become less feasible, and we can only rely on human judgment.7 That is why it is important to study what commanders find difficult when executing sea-control missions in littoral environments.

It has been shown to be fruitful, when studying the problems people face when trying to solve a task, to have a model of the task that describes what the decision maker is required to do.8 Whether that task description takes the form of a document—a formal description or formula—or an expert, the approach is similar—you compare people’s behavior to the description and try to identify where and why they differ. Since experts differ, formal descriptions are preferable, if feasible. For the sea-control task, the description can either list the problems that the commander must solve in order to get ships safely to their destinations or define the variables of interest and the states they must be in for sea control to be considered established.

To get a description of what is required to establish sea control one can study what doctrine has to say. A major U.S. Navy doctrinal publication, Naval Warfare, characterizes sea control as one of the service’s core capabilities and states that it “requires control of the surface, subsurface, and airspace and relies upon naval forces’ maintaining superior capabilities and capacities in all sea-control operations. It is established through naval, joint, or combined operations designed to secure the use of ocean and littoral areas by one’s own forces and to prevent their use by the enemy.”9 British Maritime Doctrine has a similar description of sea control: “Sea control is the condition in which one has freedom of action to use the sea for one’s own purposes in specified areas and for specified periods of time and, where necessary, to deny or limit its use to the enemy. . . . Sea control includes the airspace above the surface and the water volume and seabed below.”10 A North Atlantic Treaty Organization publication, Allied Joint Maritime Operations, relates the level of control to the level of risk: “The level of sea control required will be a balance between the desired degree of freedom of action and the degree of acceptable risk.”11 Two academic analysts offer a more minimalistic view, arguing that tying the definition of sea control to specific military objectives creates contrasts between the challenges posed by, for example, littoral environments and blue-water environments.12 To accommodate these contrasts and allow for the full range of operations, they put forward “the use of the sea as a maneuver space to achieve military objectives” as a definition of sea control.

However, two issues make it hard to use these descriptions for studying the problems commanders face in sea control tasks. To say so is not to criticize their doctrinal utility but rather to point out that for the purposes of this article, their meanings need to be expressed in a somewhat more formal way. The first issue is related to how the definitions describe when sea control has been established. All these definitions describe sea control from a general perspective, as a state, implying a line between when that state has been reached and when it has not. As result, it would be possible to use such a description to determine whether sea control has been established, at least in theory. A necessary precondition of such a description, however, is that it contain concepts—or to be more specific, a set of variables—that can be observed from the outside. For each variable there must be specified the value it must have, or the condition it must be in, in order to say that the overall state has been reached. Only then are we able to use the definition to measure whether a commander has succeeded in establishing sea control. The second issue regards the “general,” “outside” perspective that characterizes all these descriptions—a conceptual view, detached from the environment, the task, and the decision maker. In a sea-control task, however, several factors, variables, need to be considered in order to determine the degree to which the commander has managed to solve it: geography, type and duration of the operation, the enemy’s units and weapons, own resources, and the size of the region are just a few examples. A description covering all possible aspects of sea control and all possible situations would probably be quite complicated, containing many variables and many states; new variables not considered at the beginning might even have to be added as they arise.13 This is not an attractive situation for a scientific concept. Another approach would go in the other direction, stripping the definition of variables and formulating it on a very general level (the academic definition cited above is such an attempt).14 Such a definition covers a wide range of situations, but it is not very specific and provides no guidance as to when sea control has been established.

It would seem, then, that defining sea control from a general perspective is not helpful for present purposes. The point is to not separate the definition of sea control from the person trying to achieve it, or from the environment, or from the task. Such a definition would assume the perspective of the commander, describe sea control as a task that the commander has to accomplish, and lay out what is required to accomplish that task.15 Such a definition could, as we have postulated about the analytical definition we need, either describe the problems that the commander must solve in order to protect the ships or be a representation of the sea-control task. Such a description would allow systematic investigation of the effects of different tasks and different environments on the commander’s ability to establish sea control.

In fact, I argue, to investigate the concept empirically, sea control is best described from the inside. Taking the perspective of commanders trying to achieve control makes it possible to investigate systematically the problems they face and in turn, perhaps, to derive guidance for the design of training and support systems. The point of departure for such a description is the idea that securing control at sea is analogous to establishing a “field of safe travel,” a concept that has been proposed to describe the behavior of automobile drivers.16 This approach can be useful for investigating the problems commanders at sea face, and it may enrich and extend traditional thinking about sea control and how to achieve it, especially in littoral waters.

The Field of Safe Travel

Driving a car has been described analytically as locomotion through a terrain or a field of space. The primitive function of locomotion is to move an individual from one point of space to another, the “destination.” In the process obstacles are met, and locomotion must be adapted to avoid them—collision may lead to bodily injury. Locomotion by some device, such as a vehicle, is, at this level of abstraction, no different from walking, and accordingly it is chiefly guided by vision. This guidance is given in terms of a path within the visual field of the individual, such that obstacles are avoided and the destination is ultimately reached.

The visual field of a driver is selective, in that the elements of the field that are pertinent to locomotion stand out and are attended to, while irrelevant elements recede into the background. The most important part of this pertinent field is the road. It is within the boundaries of the road that the “field of safe travel” exists.17 The field of safe travel is indefinitely bounded and at any given moment comprises all the possible paths that the car may take unimpeded (see figure 1). The field of safe travel can be viewed as a “tongue” that sticks out along the road in front of the car. Its boundaries are determined by objects that should be avoided. An object has valence, positive or negative, in the sense that we want to move toward some (positive valence) and away from others (negative valence). Objects of negative valence have a sort of halo of avoidance, which can be represented by “lines of clearance” surrounding it. The closer to the object the line is, the greater the intensity of avoidance it represents. The field of safe travel itself has positive valence, the more so along its midline.18

The field of safe travel is a spatial field. It is, however, not fixed in physical space but moves with the car through space. The field is not merely a subjective experience of the driver but exists objectively as an actual field in which the car can operate safely, whether or not the driver is aware of it. During locomotion it changes constantly as the road turns and twists. It elongates and contracts, widens and narrows, as objects encroach on its boundaries.

It is now possible to investigate how the concept of a “field of safe travel” applies to naval warfare. As stated above, the purpose of sea control is to take control of maritime communications, whether for commercial shipping or naval forces. The practical problem for a commander is consequently to protect commercial vessels and warships as they move toward their destinations. These ships will be referred to as “high-value units.”

The analogy is straightforward: to make sure that the high-value units get safely to their destinations the commander must create a “field of safe travel” where they can move without risk of being sunk. At the simplest level, without the complication of hostile opposition, the problem of maneuvering a high-value unit is exactly the same as that of driving a car: make sure that it gets to its destination without running into something (that is, for a vessel, colliding or running aground). As such, there is no difference between a high-value unit’s field of safe travel and an automobile’s.

Original figure caption: “If, in this and the following figures, the page is turned around and the figure is viewed from what is now right, the reader may the better be able to empathize the situation, since he will then have the point of view of the driver of the car whose field of safe travel is under discussion.” From American Journal of Psychology. Copyright 1938 by the Board of Trustees of the University of Illinois. Used with permission of the authors and the University of Illinois Press.

The fields of individual ships are, however, not of interest here and will not be further discussed; our focus is the field of the commander of the naval operation. In that field, the most pertinent element of the environment is not the terrain (though coasts and islands delimit how the ships can move) but the enemy. Consequently, the boundaries of the commander’s field of safe travel are determined most importantly by enemy units that threaten to sink the commander’s high-value units (see figure 2). In contrast to fixed objects in a driver’s field of safe travel, islands and coastlines may actually have positive valences for a commander, as they can offer protection. Nevertheless, the definition of the field remains the same: the commander’s field of safe travel comprises all the possible paths that the high-value units can take unimpeded.

Though the analogy is straightforward, there are several differences between the driver’s field of safe travel and that of the commander. First, the driver of a car has limited ability to influence the shape of the field of safe travel and can only see and react to obstacles that encroach on the field. Commanders, on the other hand, can actively shape the field of safe travel and have powerful means to do so: they can scout threatening areas to determine whether enemy units are present, and if they detect a threat they can eliminate it by applying deadly force. Second, the commander is up against an enemy who means to do harm. An opponent who uses cover and deception can make it more difficult to establish the requisite field.

For the commander of a naval operation, the field of safe travel is delimited not only by the terrain but also by, most importantly, threatening enemy units.

Third, the commander’s field of safe travel cannot, like the field of a driver of an automobile, be directly perceived; it is too vast. Instead, the commander must derive the field, using data provided by sensors carried by the units in the force. As will be seen later, this difference complicates matters for the commander. Nevertheless, it is important at this point to notice that the field of safe travel is not merely a subjective experience of the commander but exists as an objective field where the commander’s ships can move safely.

The Minimum Safety Zone

In driving, collisions are avoided by one of two methods—changing the direction or stopping the locomotion.19 Changing direction is done by steering. Sometimes, however, the field of safe travel is cut off, for example, when another car turns onto the road from a side street. In these situations steering is not enough, and the driver has to slow down to avoid a collision. Another field concept describes how drivers decelerate—the “minimum stopping zone,” which denotes the minimum spatial field a driver needs to bring the vehicle to a stop (see figure 1).20 Deceleration (or the degree of braking) is proportional to the speed at which the forward boundary of the field of safe travel approaches the edge of the minimum stopping zone.

For the commander of a naval operation, the field of safe travel is delimited not only by the terrain but also by, most importantly, threatening enemy units. The commander uses a related field concept to determine whether action is needed to prevent the high-value units from being sunk—the “minimum safety zone” (see figure 3). The minimum safety zone is a field the size of which is determined by the range of a specific enemy weapon; there exists one minimum safety zone for each type of enemy weapon. The field denotes how close to the high-value units an enemy unit carrying that weapon can be allowed before the enemy unit can sink the high-value units using that specific weapon.21 For example, suppose an enemy ship has an antiship gun with a range of ten thousand meters. In this case, the minimum safety zone for that gun would be a circle with a radius of ten thousand meters around each high-value unit.

From this it follows that there exist as many fields of safe travel as there are minimum safety zones; minimum safety zones and fields of safe travel always come in pairs. For example, the enemy may have a long-range antiship missile that can be fired from surface ships and a medium-range torpedo that can be fired from submarines. This creates two separate pairs of fields of safe travel and minimum safety zones—one for the antiship missile and one for the torpedo. Consequently, to make sure that the high-value unit is not sunk, each minimum safety zone must be completely contained within its corresponding field of safe travel for the duration of the voyage.

Also, the shape of the minimum safety zone varies according to the type of weapon it represents (see figure 3). The shape is determined by the relative speeds of the weapon and the target and their relative headings when the weapon is fired. Suppose a high-speed antiship missile is fired toward a slow-moving high-value unit (see figure 3a). It will take the missile about five minutes to reach its target if the speed of the missile and the range to the target are, respectively, 645 knots and about fifty-four nautical miles. The distance the high-value unit can move during this time at twenty-five knots is about four thousand meters. Thus, the difference in time between when the missile is fired with the high-value unit heading toward it or moving away is negligible; the minimum safety zone can be considered circular. Now consider firing a medium-range torpedo at the same high-value unit. The torpedo has a speed of, say, fifty knots and a range of 25 nautical miles. If the enemy unit fires this torpedo when the high-value unit is heading toward it the theoretical range becomes about thirty-seven nautical miles (it takes thirty minutes for the torpedo to travel its maximum distance, in which time the high-value unit can move 12.5 nautical miles closer). On the other hand, if it fires when the high-value unit is moving away, the range drops to only 12.5 nautical miles. Thus, the shape of the minimum safety zone for the torpedo will be more or less elliptical, with the high-value unit positioned toward its far end (see figure 3b).

The dotted line denotes the minimum safety zone. Its size is determined by the range of an enemy weapon. The minimum safety zone must be completely contained within its corresponding field of safe travel for the duration of the transit, or there will be a risk of loss. In (b) the shape of the minimum safety zone depends on the relative velocities (speed and firing angle) of the weapon and high-value units. To fire a torpedo when the target is moving away, the submarine must come much closer than must a submarine firing at a target moving toward it.

What minimum safety zone the commander uses when encountering a new contact depends on how well the contact is classified. If the commander knows what type of enemy unit is approaching, the proper, specific minimum safety zone is applied. If there is uncertainty, the commander must assume the largest minimum safety zone for that class of contacts. For example, if the commander knows that only surface ships can carry long-range antiship missiles, the minimum safety zone for those missiles must be assumed for an unidentified radar contact—that is, of the class of surface contacts. For the submarine screen, however, the minimum safety zone can be based on the medium-range torpedo—the class of underwater contacts. For the driver of an automobile, braking is a reaction to the threat of crashing into an object and it is initiated when the forward boundary of the field of safe travel recedes toward the minimum stopping zone. In a similar way, the commander of a naval operation reacts when the field of safe travel recedes toward the minimum safety zone—that is, when a threat develops toward the high-value units. In contrast to the automobile driver, however, the commander has three ways of handling a threat: move the high-value units away from the threat, order subordinate units to take action against the threat, or receive the attack and defend. Either way, to establish whether a threat is developing, the commander must be able to determine whether the field of safe travel is receding toward the minimum safety zone.

Dr. Waldenström works at the Institution of War Studies at the Swedish National Defence College. He is an officer in the Swedish Navy and holds an MSc in computer science and a PhD in computer and systems sciences. His dissertation focused on human factors in command and control and investigated a support system for naval warfare tasks. Currently he is working as lead scientist at the school’s war-gaming section, and his research focuses on learning aspects of war games.


1. Robert C. Rubel, “Talking about Sea Control,” Naval War College Review 63, no. 4 (Autumn 2010), pp. 38–47.

2. Ibid.; Wayne P. Hughes, Jr., Fleet Tactics and Coastal Combat (Annapolis, Md.: Naval Institute Press, 2000).

3. Sir Julian Corbett, Some Principles of Maritime Strategy (1911; repr. Annapolis, Md.: Naval Institute Press, 1988), pp. 122–24.

4. Ibid.

5. For descriptions of littoral navies, see, among others, J. Børresen, “The Seapower of the Coastal State,” Journal of Strategic Studies 17,
no. 1 (1994), pp. 148–75; Tim Sloth Joergensen, “U.S. Navy Operations in Littoral Waters: 2000 and Beyond,” Naval War College Review
51, no. 2 (Spring 1998), pp. 20–29.

6. Hughes, Fleet Tactics and Coastal Combat; Milan Vego, Naval Strategy and Operations in Narrow Seas, 2nd ed. (Portland, Ore.: Frank Cass, 1999); John F. G. Wade, “Navy Tactics, Doctrine, and Training Requirements for Littoral Warfare” (thesis, U.S. Naval Postgraduate School, Monterey, Calif., June 1996); V. Addison and D. Dominy, “Got Sea Control?,” U.S. Naval Institute Proceedings 136, no. 3

7. See the discussion of the C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance) system as an artifact in Berndt Brehmer, “Command and Control Research Is a ‘Science of the Artificial’” (paper delivered to the fifteenth International Command and Control Research and Technology Symposium, Seattle, Wash., 2010).

8. An example that has generated a Nobel Prize winner is “heuristics and biases” decisionmaking research, where human judgment is compared to statistical models. See D. Kahneman, P. Slovic, and A. Tversky, Judgment under Uncertainty: Heuristics and Biases (New York: Cambridge Univ. Press, 1982); and T. Gilovich, D. Griffin, and D. Kahneman, eds., Heuristics and Biases (New York: Cambridge Univ. Press, 2002). For a more general overview,
see, for example, Paul R. Kleindorfer, Howard C. Kunreuther, and Paul J. Schoemaker, Decision Sciences: An Integrative Approach (Cambridge, U.K.: Cambridge Univ. Press, 1993).

9. U.S. Navy Dept., Naval Warfare, Naval Doctrine Publication 1 (Washington, D.C.: 2010) [hereafter NDP-1], p. 28.

10. Ministry of Defence, British Maritime Doctrine (BR1806), 3rd ed. (Norwich, U.K.: by command of the Defence Council, 2004), pp. 41–42.

11. North Atlantic Treaty Organization, Allied Joint Maritime Operations, AJP 3.1 (Brussels: NATO Standardization Agency, 2004), chap. 1, p. 8.

12. Addison and Dominy, “Got Sea Control?”

13. As it was necessary for Ptolemy to introduce epicycles in order to handle the irregular movement of planets in his geocentric description of the solar system.

14. Addison and Dominy, “Got Sea Control?”

15. There are several analyses that describe the kinds of missions a commander has to execute in order to achieve sea control. See, for example, Frank Uhlig, “How Navies Fight, and Why,” Naval War College Review NWC_Winter2013Review.indd 98 11/1/12 10:57 AM 22
Naval War College Review, Vol. 66 [2013], No. 1, Art. 7
WALDENSTRÖM 99 48, no. 1 (Winter 1995), pp. 34–49; Uhlig,
“The Constants of Naval Warfare,” Naval War College Review 50, no. 2 (Spring 1997), pp. 92–105; and NDP-1. What missions have to be executed, however, do not constitute a description of what has to be accomplished in order to establish sea control. The missions that can be executed represent the means
available to establish sea control—that is, the commander’s ways of bringing about the state of sea control.

16. J. Gibson and L. Crooks, “A Theoretical Field Analysis of Automobile-Driving,” American Journal of Psychology 51, no. 3 (July 1938), pp.

17. Ibid., p. 454.

18. The concept of ”valence” is from ibid., p. 455.

19. Ibid., p. 456.

20. Ibid., p. 457.

21. The “minimum safety zone” is just another term describing how far out from the field of safe travel an enemy contact starts to encroach on it. To use the field and anchor it to the high-value units is convenient, however, and makes it possible to use the same concept for all enemy weapons, antiship missiles as well as mines. Further, the observations of naval officers when they solve sea-control tasks have revealed that they use tools in the command-and-control systems on board their ships to visualize these zones—circular regions around high-value units or corridors where high-value units will move.

Featured Image: ATLANTIC OCEAN (May 13, 2010) Operations Specialist 3rd Class Gregory L. Gray mans his station in the Combat Direction Center aboard the aircraft carrier USS Enterprise (CVN 65). (U.S. Navy photo by Mass Communication Specialist 3rd Class Brooks B. Patton Jr./Released)