Hey kook - These are floatation devices only! I am not sure weather they are Coast Guard Type one or type Two ( type two holds the head of an unconscious victim above the water and is rated for offshore ). If you are buying them for floatation devices they look cool. If you are trying to simulate the protection of a Lifeline jacket it's like comparing a 1.5hp outboard to a 900SC!
As an ex competitive waterskier, I have taken many falls in the 40 to 50 mph range. I am already on the water when these falls occur ( translated - I only fall a couple of feet in height ). On numerous occasions, the ski goes one way, my body another and the lifejacket is floating by itself ten feet away.
A boating accident has a lot more forces at work. The height, body contortions and many other factors are at work. I am not lecturing. I am merely suggesting that you should not be lulled into the notion that you are getting the protection of a Lifeline jacket. Surely, wearing a personal flotation device while boating is better than not wearing anything. If you need a Lifeline jacket, get it. It is a small price to pay for life & health.