While we're on the subject of life preservers, here's something to consider: before you spend a lot of money, and bet your life (and the lives of your crew) in the process, borrow a Type I, II, III or V from someone, put it on, wear it for a while, and then jump in the water, and see how you float. Here's what I've found, and concluded:
Type I: bulky to wear, but keeps you floating, face up, with your head out of the water. These are the best USCG approved devices, and what you want to be wearing if you actually go overboard, or if things get really sporty. But, they are so bulky that few people are able to wear them routinely. We don't carry them on board, but would if we went offshore more frequently.
Type II: same as Type I, but not as bulky, and you don't float quite as well. We carry these as spares, for passengers, and to meet the minimum USCG requirements.
Type III: very convenient to wear, little restriction of motion, although a little warm during the summer. And it will keep you floating. But, if you strike your head on the way overboard, or have some other disabling injury, you will be found floating, dead, face down in the water. Type III is the standard issue USCGAUX device, primarily because of wearability. And, if you're conscious, it keeps you afloat reasonably well. But before you take great comfort in a Type III, try being in the water, holding your breath, and going totally limp: pretend you're unconscious. My experience is that it takes about 15 seconds for a Type III to have you face down. How long it takes to drown, once your face is in the water, will vary with the individual, and the water conditions. Estimate how long it will take to accomplish a man overboard extraction, and I think the bottom line is that if you hit your head on the way overboard, or for any reason become unconscious in the water, the rescue of someone wearing a Type III will quickly turn into a body recovery.
Type V: AKA, inflatable. Very convenient to wear, and will keep you floating on your back, face up and mouth and nose clear of the water. They are so effective that if you want to swim after one of these have inflated, you need to bleed out some air (actually, CO2). You can get the kind that are manual inflate only, but if you hit your head on the way overboard, you're like the fellow with a Type III, only your body will be a little harder to locate. You can also get the auto/manual inflate version, which is what I was wearing when I went overboard in the shipping lanes of the Chesapeake, while boating solo. That thing inflated before I figured out that I had gone overboard, and had me floating like a cork, face up and clear. These have to be worn to be counted (throw a few cheap Type II's on board for emergencies, and to meet the basic regulatory requirements). But, face it, any jacket has to be worn to do you much good. I have about 950 underway hours on the CD22, and have worn a Type V inflatable for most of them. Of the two devices we carry, we've had one emergency inflate, as mentioned above, and two false inflates. One false inflate was during transport, when the device was left on the cabin floor, bounding up and down. The other was after a driving rainstorm, when the device was stored horizontally, rather then vertically, and water allowed to run up toward the inflate mechanism.
