How Navy SEALs Use Watches to Navigate Underwater

Warfare & Watches Have Changed, But For Maritime Special Operators, a Timepiece Remains a Vital Tool of Underwater Navigation 

By Benjamin Lowry 

You’ve seen it before. Whether in film, an old-school recruiting ad, a documentary, or a corny TV series, the scene where a team of Navy SEALs in diving gear clandestinely break the water’s surface on a faraway beach in the dead of night is pervasive. The lighting is typically better in Hollywood’s portrayal, but these types of missions are real and constitute the bread and butter of any legitimate maritime special operations force, whether SEALs, Army Special Forces Divers, or Commando Hubert Combat swimmers.

For combat divers, navigating to an objective underwater depends on a specialized tool called an attack board, and watches play an essential role. (Photo Credit: US Navy)

But how, after parachuting into the sea or being dropped off by an awaiting small boat, submarine, or mini-submersible, do frogmen navigate to the beach or another objective, often in total darkness, in the first place? As it turns out, for combat divers both then and now, a dive watch is at the center of the action. 

For this Dispatch, we sat down with our friend and W.O.E. interview alum, retired Navy SEAL Dave Hall, to talk about the navigation or “attack” board, a handheld underwater navigational tool used by military divers. Digital tech may have forever changed modern warfare, reducing the role played by timepieces in many cases, but for combat diving, a capable watch on an attack board is still an essential tool. 

The Combat Diver’s Attack Board 

One of Dave’s old attack boards paired with an issued Casio G-Shock DW6600-1V. (Photo Credit: W.O.E./James Rupley)

A combat diver’s navigation or attack board is a plastic, resin, or sometimes wooden diving tool designed to hold three key instruments, working for a diver much as an instrument panel in the cockpit does for a pilot. When I asked him for an attack board knowledge transfer, Dave explained, “The three things you have to know and monitor for accurate underwater navigation are: depth, direction, and time.” 

Essential for safety, the first component is a depth gauge. Most combat divers relying on pure oxygen rebreathers spend most of their time at 20 feet or shallower. Any deeper, and a diver risks “oxygen toxicity”, which can result in visual changes, strange ear noises, nausea, and even sudden seizures, all of which are problematic if you’re in the middle of a combat dive/swim. “Most dudes stay around 15 feet to maintain a margin of safety, and they can creep up even shallower if necessary,” Dave said, adding, “Most scuba-oriented depth gauges cover a much wider depth range than combat divers need on pure O2, so we’d tape over everything but the part that shows the first few meters.” 

A Green Beret assigned to 10th Special Forces Group (Airborne) checks his navigation, or “attack”, board during annual dive requalification training at Marine Corps Base Camp Pendleton, California, on 12 July 2026. (Photo Credit: US Army)

Second is a submersible compass, which is typically oil-filled to prevent the ingress of water. This allows a combat diver to establish and maintain an azimuth or “heading”, i.e., to swim in a straight line towards the next objective or a planned turn without straying off course. Tides and currents also play a major role and have to be accounted for in the mission planning stage. Underwater navigational routes can be long and complex, and to manage the time and distances of “legs” between turns, the submersible compass is paired with another essential tool: a watch. 

Strapped alongside the compass and depth gauge, the watch is the final piece of the attack board puzzle, utilized primarily as a countdown timer to manage the length of time for each individual leg of a predetermined route. Distance is managed through fin kicks, a known value learned through testing in a pool or ideally over a measured distance in open water. According to Dave, it works like this: 

“If a particular swimmer knows they kick 64 times to go 100 yards, and that it takes them three minutes, then they’d simply have to set the watch on their board to count down from thirty minutes and count to 640 (or 64 ten times) to know they’ve completed 1000 yards underwater, at which point it would be time to execute a turn and start the next leg. If they did everything right, they hit the correct number of fin kicks right as the time expires on the watch on their board. All the while, they are monitoring their azimuth with the compass and keeping an eye on their depth.”

Marines with 2d Reconnaissance (Recon) Battalion, 2d Marine Division conduct buddy pair navigation dive operations using an attack board. (Photo Credit: USMC)

Because a lot is going on, combat diving is always executed in pairs, with one diver “driving” (i.e., navigating) through the attack board, and the other “riding”, usually at a slightly shallower depth so that they can maintain a better sense of situational awareness compared to the driver who is locked into the board. This is not to say that the rider is passive. If necessary, the divers’ roles are interchangeable, and a complex series of hand signals is used to remind either diver about an upcoming turn or in the event of a navigational misstep. Both divers also typically wear a watch on their wrists to manage overall dive time. 

If it sounds complicated, it’s because it is, and underwater navigation is a skill set that is learned by amphibious special operators during initial dive training and mastered over the course of a career. 

“In the late 80s to mid-90s, at least at SEAL Team Two, if you couldn’t successfully place a limpet on a ship’s hull without being busted by OPFOR whenever you were tasked to do so, you were considered somewhat useless. Maintaining your combat swimmer skills was prioritized higher than the other skills, like CQB. During the GWOT, the role of combat diving in the Teams faded, but in the last few years, in light of current events, the guys have quickly worked to reestablish these capabilities. They’re doing some really impressive things.” 

Despite advancements in the technology of special operations, most of the combat diver’s core tools, including the attack board, are largely unchanged from the earliest days of maritime special operations. 

Attack Board in Special Operations - Then & Now 

In a still from the 1957 film The Navy Frogmen, a UDT man wears a compass and depth gauge in the pre-attack board era. (Photo Credit: US National Archive)

“In early photographs of UDT dudes, you’d see them with a compass, depth gauge, and sometimes also a watch, spread across their two wrists. They’d essentially make an L with their arms while pointing the direction of travel, acting as a sort of rudimentary navigation system, but it’s not comfortable or convenient to swim like that for long periods. As combat diving developed, with input coming from the OSS Maritime Unit’s wartime experiences, the need for a place for all of that navigational equipment to live spurred guys to build simple boards of their own, initially out of wood.” 

Early handmade wooden boards gave way to small-batch resin models and eventually plastic boards with integrated compasses and mounting points for the watch and depth gauge. 

“When I got into the Teams in the late 80s, there were still a few resin or wood boards around, but by the time I got out, the Teams were mostly using plastic attack boards. Some modern boards are electronic and a few even integrate a diving computer, but most of the time, it’s still a watch, a compass, and a depth gauge. Not everything has to be high tech.” 

A Tornek-Rayville TR-660 paired with a US Navy-issued attack board. (Photo Credit: Brock Stevens)

Frogmen attach tethers to their attack boards, because losing one on a mission would be a really big problem. The boards typically have dedicated slots to hold a chem light, which is mostly covered or taped up to emit only the amount of illumination absolutely necessary to read their compass, depth gauge, and watch. There are now numerous options for purpose-built attack boards, but one of the most common in the United States military is the TAC-100 produced by RJE International, which comes from the factory with any of several inexpensive digital watches.

The Watches of Underwater Navigation

Even in the mid-90s, a diver from the French Armée de Terre opted for an analog Jacques Bianchi JB300 on his attack board. (Photo Credit: Watchuseek)

Historically, when dive watches were indispensable analog mechanical tools, military divers would take the watch off their wrist to use for underwater navigation if they didn’t have a second timepiece. During the golden age of tool watches, when SEALs and French Commando Hubert combat swimmers were issued Tudor Submariners, that meant the Tudor took a ride on the board. Given that watches like the Tudor Sub and the later 6309 were equipped with elapsed time or “count-up” as opposed to count-down bezels, the diver had to use a larger portion of their brain, but the job still got done. 

There are modern exceptions, including the original Pelagos FXD, which is equipped with a count-down bezel at Commando Hubert’s request for this very reason, and the Sinn UX S Kampfschwimmer utilized by German maritime commandos, but for the most part, digital dive watches took over underwater nav duties upon their introduction in the 1980s. 

Ze Germans also sometimes pair their issued Sinn UX S models with their attack boards. (Photo Credit: @kampfschwimmer_eckernfoerde)

Today, in most cases, that means an OEM attack board will be complete with a Casio G-Shock, and most navigation board manufacturers opt for the simpler G-Shock models, including the DW6900-1V and the DW9052-1V, both of which also carry NATO Stock Numbers. According to Dave, “The watch batteries tended to wear out faster than normal land use from using the backlight pretty often during a night dive, but a G-Shock in the Teams was essentially disposable. You’d just grab a new one from supply and off you go.” 

An intriguing outlier we have not discussed before, the Nixon Regulus MK-1, a digital watch from a brand typically associated with fashion, is also sometimes stocked with a navigation board, so it must work well enough. Beyond that, military divers may opt to pair their issued or personally-purchased Garmin Descent, Fenix, or Tactix models with their boards. Two key factors make digital watches the stronger option for service on a combat diver’s attack board. One is the aforementioned countdown timing functionality. The other is illumination, as digital dive watches typically integrate an on-demand backlight feature that is perfect for a combat diver’s needs. 

A Navy SEAL prepares for a dive with a Nixon Regulus MK-1 on his attack board and a G-Shock DW9052-1V on his wrist. (Photo Credit: US Navy)

Final Thoughts 

In an era when satellites, encrypted radios, and advanced dive computers have transformed almost every aspect of modern warfare, it's remarkable that one of the combat diver's most trusted navigational tools remains a simple wristwatch. Mounted to an attack board alongside a compass and depth gauge, the watch is more than a backup; it is a vital component in a system built on discipline, repetition, and absolute trust in one's equipment. 

Whether it's a battered issued G-Shock, a vintage Tudor Submariner, or a modern Garmin smartwatch, the timepiece continues to play a quiet but essential role in helping maritime special operators find their way through the darkness beneath the surface. To quote a popular adage from a Bond film, “Sometimes the old ways are the best.” 

Thanks again to Dave Hall for sharing his knowledge and experience with us. Click HERE to learn more about Dave’s career and watches. 

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