designed to stop you swimming
life jackets are not there to assist you in swimming, many of us would prefer not to inflate them until NEEDED...if you have to swim to a raft, then board int the life jacket is a hinderance, not a help. Most people swim face down, and a life jactets centre of bouyance should be behind your neck thus to force you face up... this is an unnatural swim position unless you are a scuba diver, in which case it is a natural surface swim position.
Remember there is a front and a back....remember when you have an inflated jacket and JUMP into the water, the jacket tries NOT to sink, your body tries TO sink. The jacket will win and it can hurt....the jacket then rides up over your upper body and tries to drown you.
Boarding the raft is a skill, and does need practice....I suggest that you avoid being first and last....then someone can pull and push you on board....
There are many different types of jacket, and different types of fixing straps, belts etc. I would not buy one, as it will end up being different to your company standard.
lastly a standard jacket, can turn you face down into the water........then you drown....this was the result of a survey by one of the sailing magazines.
glf