A watertight thermal protective suit worn in cold water abandonment that significantly extends survival time.
Quick facts
Regulation
SOLAS Chapter III
In practice
Each officer and rating must have a personally fitted immersion suit stowed in their cabin or at the muster station, depending on the vessel's arrangement. Passenger vessels carry suits for all persons on board in the navigation area. Crew must practise donning the suit regularly during drills, as dexterity and speed are impaired by cold, darkness, or the stress of an emergency.
Regulatory detail & full definition
An immersion suit — commonly called a survival suit — is a watertight garment designed to protect a person in cold water by retaining body heat and preventing rapid hypothermia after abandoning ship. SOLAS Chapter III and the LSA Code prescribe performance standards: the suit must allow the wearer to don it unaided in under two minutes, keep the wearer afloat face-up, and maintain core body temperature in water below 2°C for a specified period.
Each officer and rating must have a personally fitted immersion suit stowed in their cabin or at the muster station, depending on the vessel's arrangement. Passenger vessels carry suits for all persons on board in the navigation area. Crew must practise donning the suit regularly during drills, as dexterity and speed are impaired by cold, darkness, or the stress of an emergency.
Port state control inspectors check that suits are within service life, not damaged, and correctly sized for the wearer. Zips must be fully operational — a stuck zip is a frequent deficiency. Manufacturers specify inspection intervals and hydrostatic testing requirements. In polar and sub-arctic trades, the Polar Code introduces additional requirements for thermal protection, and officers must understand the difference between an immersion suit's performance in temperate waters versus Arctic conditions.