What is the difference between a life jacket and a buoyancy aid?
The difference between a lifejacket and a buoyancy aid is that a lifejacket is a device or garment designed to help you float on water when conscious or unconscious while a buoyancy aid is a device or garment that helps you to provide a particular amount of buoyancy and increases the likelihood of rescuing incapacitated user. Without your contribution buoyancy cannot help you under any given circumstances.
1 Additional Answer
A lifejacket is designed to help you float (conscious or unconscious) and keep your airway out of the water while a buoyancy aid is simply there to provide buoyancy, but it won't turn an unconscious casualty the right way up.
A personal flotation device (abbreviated as PFD; also referred to as a life jacket, life preserver, Mae West, life vest, life saver, cork jacket, buoyancy aid or flotation suit) is piece of equipment designed...