The Submarine Escape Suit MK9 was developed for use by the United Kingdom's Royal Navy in 1993 by Beautfort Air-Sea Equipment. The suit was made from nylon, rubber, leather, plastic and metal, with a height of 1980 mm and chest of 556 mm. The suit is a bright orange dayglow one-piece suit with hood, integrated boots and gloves and breathing system. These suits were manufactured in small numbers and remain in use, with alterations and advancements, with the Royal Navy as of early 2020.
The suit was designed for submariners to escape from a sunken or otherwise damaged or disabled submarine from a depth down to 600 ft (183 m). The suit is a combined whole-body and one-man life raft designed to protect the user against hypothermia and offering full flotation. The suit weighs 7kgs.
When used, the Submarine Escape Suit MK9's double skinned nylon fabric fully inflates three air chambers. The chest inflates through a yellow valve on the left hand. The front and back of the suit inflate through two valves on the right wrist. Two CO2 gas canisters were used to inflate the suit. And the suits clear plastic face splash shield was used when floating while an inner neoprene hood was used for comfort.
Included with the suit are a distress whistle, a strobe light powered by a saltwater battery, SOLAS reflective panels, three fingered leather mitts, thermal outer gloves stored under the forearms, a nose clip, adjustable velcro ankle and feet straps and a tube for attaching a catheter. The suits came with toggles to attach multiple suits together.