Getting out of a plunging Navy jet is simple: Pull the eject lever. Escaping from a disabled nuclear sub? A bit trickier. You first have to climb into a full-body buoyancy suit (which later transforms into a one-man life raft), then scramble into an escape chamber, seal the door, inflate the suit, and hold on tight as the lock is flooded with icy water. Then open the hatch and try not to panic during that long float to the surface. Luckily, the US Naval School in New London, Connecticut, now has a facility that lets sailors perform not-so-dry runs. The 37-foot-deep, 84,000-gallon tank — the first of its kind in the US — offers exact replicas of the escape chambers in Virginia— and Los Angeles-class submarines. Perfect for teaching sailors how to rise to the top.

Four Steps to Avoiding a Watery Grave

1. Below the tank, a trainee zips into a buoyancy suit, then clambers up into the escape chamber.



2.Inside, the sailor plugs into an air valve to start inflating the suit while an instructor attaches a safety tether. The trainee then grabs onto handles as the water pours in.



3. Once the compartment is flooded, a hatch is opened overhead. The tether is released, and the buoyancy of the suit carries the sailor to the surface, where additional instructors wait.



4. Upon surfacing, which in a real emergency would be in the middle of the ocean, a raft deploys from a hip pouch on the suit, puffing out like a blowfish. It may be a little undignified, but it beats sitting in a steel casket on the seafloor.