Submarine Escape Immersion Equipment
Submarine Escape Immersion Equipment (SEIE) MK-10, also known as Submarine Escape and Immersion Equipment is a British designed whole-body suit and one-man life raft that allows submariners to escape from a sunken submarine. The suit provides protection against hypothermia and is rapidly replacing the Steinke hood rescue device. The suit allows survivors to escape a disabled submarine at depths down to 600 feet (183 m), at a rate of eight or more men per hour.
The SEIE is designed to enable a free ascent from a stricken submarine and to provide protection for the submariner on reaching the surface until rescued. The assembly comprises a submarine escape and immersion suit, an inner thermal liner, and a gas-inflated single-seat life raft, all contained in an outer protective stowage compartment.
The suit not only keeps the escapee dry and protected from cold shock during escape, but also acts as a thermally efficient immersion suit on reaching the surface. Full protection is therefore provided while deploying and boarding the life raft. The suit provides sufficient lifting force to take the escapee from the submarine to the surface at a safe speed of approximately two to three meters per second.
The British SEIE Mk-10 has been used in Royal Navy Submarines for a number of years.
The British designed SEIE MK-10 is scheduled to replace all Steinke hoods aboard U.S. Navy submarines. The reconfiguration of escape trunks and training of the crews are requirements prior to installing the new system.
Several submarines have already installed the new system. USS Key West (SSN-722) is one of 17 attack submarines homeported in Pearl Harbor slated to implement the new survival suit and accompanying equipment.
The Steinke hood was designed for the same circumstances, but did not include a full-body, thermally insulated suit or life raft. It was at best a last-ditch survival device but would not protect submariners from hypothermia or provide shelter or visibility at the surface, as the SEIE is designed to do.
In the event of an emergency, the SEIE might save submariners from an otherwise perilous fate. However, the device is designed to be a last resort in the event of a submarine emergency at sea. The goal in the event of a submarine mishap is survival. The second is rescue with a submarine rescue vehicle. Lastly, if a rescue vehicle is not available or cannot connect to a stricken submarine, the crew can escape using the SEIE.
Optimally, a rescue vehicle is preferred as it allows crewmembers to survive with essentially no injuries since they are protected from the great amount of pressure at ocean depths. A rescue vehicle connects directly to the escape hatch of a submarine, eliminating the threat of exposure to cold water and extreme pressure.
In addition, the primary benefit of rescue before resorting to escape with the SEIE is that there would be resources available, including a recompression chamber, should it be needed by the rescued crewmembers.
However, unlike the Steinke Hood, the suit provides good protection from decompression sickness, hypothermia, and climatic exposure.

# Notes
- Most of the information in this article was current in 2004. As of 2007, the number of submarines equipped with the SEIE is likely much higher.
-  Jump up to: 1.0 1.1 COMPSUBPAC press release, 2004.