Groton, Connecticut. (July 27, 2024): Being trapped hundreds of feet below the waves must be the darkest nightmare for every submariner. In this photo by Lauren Laughlin, students participate in surface survival training at the Navy Surface Survival Naval Submarine School. The course uses a pressurized submarine escape training facility to teach students how to survive a worst-case scenario where they perform an emergency escape from a submarine. The training teaches everything from medical physiology involved, how to surface safely, and even the proper way to man lifeboats on the surface.

The first goal is to understand human physiology and what happens to a body as it surfaces from deep water. The concern is pulmonary overinflation syndrome, a condition caused by gas-filled spaces in the lung expanding as a person surfaces. Sailors are taught to never hold their breath but instead slowly release air in short bubble bursts as they rise to the surface. Students practice this technique in a real-time setting via a pressurized dive chamber that simulates being sixty feet below the surface. The 84,000-gallon tank is heated to ninety degrees and pressure is increased until it reaches “escape depth” or six hundred feet.

Monitored by a medical technician, students take a deep breath, submerge into the tank, and start blowing bubbles to slowly release the pressure on their lungs. Here they practice getting used to never holding their breath while remaining calm as they ascend. Once on the surface, students don bright orange suits and practice getting into a life raft, unassisted.

Through this exhaustive training, the Navy wants to do all it can to help crews successfully escape a Sailors’ worst nightmare.