There are different types, some self inflating, some like a vest, some like a fishing vest. I have a vest type, and am considering a fishing vest type. Some like self inflating ones, and they have their uses, but can keep ya inside a boat if in the cabin and it capsizes. Different vests for different uses. The vest type is pretty practical i think, and don't get in the way like the style with floation in front, and a pad behind the head. The ones with floatation in front with a pad behind the head will roll ya upright and hold your head outa the water if ya unconsious. Get the right size for ya, so it does its job and ya can still move around. Back when I was a kid I put one on for an adult, and it laid me on my back, it was too much for my weight.
there are many types of pfd's and most are not fishing friendly HAHAHAH that is the main problem in keeping the pfd on its in the dang way , some usefull info http://www.boatsafe.com/nauticalknowhow/pfdbasics.htm if u don't want to copy n paste that link then read my crappy spelling and stay with me here haha,
type I offshore Life Jacket , for open, rough or remote water, where rescue may be slow-coming <------ somthing to think about and these are mostly big bulky turds that rub the arms raw when fishing for any length of time and most of these types will force ur body to float face up and out of the water
near-shore buoyant Vest, Good for calm or inland water, or where there is a good chance of fast rescue and slighly less bulky but still chaffs the skin and some of these types will not force the body to float face up .. will i have a snerkle?
type III Good for conscious users in inland water and where there is good chance of fast rescue. and most of the time the most comfy to wear .... yea rite and the cheap ones often scratch the skin * the ends of the straps from being melted at the factory and will not turn the body face up and is not good for rough waters . i have found some pretty comfy ones used for knee boarding or wake boarding at wally world by the ski ropes they are not too bad gl and be safe