Steinke hood

A Steinke hood, named for its inventor, Lieutenant Harris Steinke, is a device designed to aid escape from a sunken submarine, essentially an inflatable life jacket with a hood that completely encloses the wearer's head, trapping a bubble of breathing air. An advancement over its predecessor, the Momsen lung, it was standard equipment in all submarines of the United States Navy throughout the Cold War period. The U.S. Navy has replaced Steinke hoods on U.S. submarines with escape suits called Submarine Escape Immersion Equipment.