Pug In Life Jacket

Devices designed and approved by authorities for use by civilians (recreational boaters, sailors, canoeists, kayakers, etc.) differ from those designed for use by passengers and crew of aircraft (helicopters, airplanes) and of commercial vessels (tugs, passenger ferries, cargo ships). Devices used by military (army, air force, special forces, marines, navy, coast guard) and police and enforcement agencies generally have features not found on civilian or commercial models, for example compatibility with other worn kit (e.g. survival vest, bullet proof vest/body armor, equipment harness, rappelling harness, parachute) and use of ballistic nylon cloth to protect pressurized carbon dioxide (CO2) canisters used for inflating the vest from injuring the wearer if struck by a round from a firearm. The ballistic cloth keeps the fragments from the canister from becoming shrapnel injurious to the user.
PFDs are available in different sizes and different designs purposed for various levels of protection.
The University of Victoria in British Columbia (province) Canada pioneered research and development into the "Floater Coat" (patented UVic Thermo Float PFD), which provides superior protection from cold water immersion (immersion hypothermia) through the incorporation of a neoprene rubber "diaper" that seals the user's upper thigh/groin region from otherwise cold, flushing and debilitating water.