A Buoyancy Aid is designed to do exactly what it says it does, its a Buoyancy Aid, unlike a Lifejacket which is quaranteed to keep your head above the water if you should be unconsious, and put you on your back by turning you in the correct direct to help against drowning a Bouyancy aid will hold your weight in the water more like a cork would (i.e Vertically), this enables the person to easily get back to the boat and get inside.
