Think about the water environment where you plan to adventure. No matter what your pastime has in store, ensure that you choose a life jacket that delivers a snug, secure fit without interfering with movement.
For children, look for youth-sized life vests that are appropriate for a child's age range, including infant life jackets for little ones weighing up to 30 pounds. Bright vests ensure young swimmers are visible in any water condition.
When you are in the water, you feel much lighter. That's because your body has displaced water that is pushing back and creating buoyancy. A life jacket is filled with a very light material, usually foam, that can displace alot of water compared to its weight. A cubic foot of foam weighs about one pound. It will float on top of the water because it only has to displace one pound of water.
Because your body already has some buoyancy, a life jacket doesn't need to support all of your weight. It just needs to displace enough to keep your head above the water.
It is important to get a life jacket that fits you properly. It won't be much use if it's too big and you slip out of it. Also, choose a life jacket that's designed for the activity you are doing. Off-shore life jackets are designed to keep you floating with your head above the water even in rough sea conditions, while life jackets designed for water skiers help you float in calm water and can also protect you from impact injuries.
Life jackets also help your body retain heat if you should fall into cold water.
Orange is a great color for life jackets because it is a very bright color that you rarely find in nature. If you are trying to rescue someone who has fallen overboard, you need to be able to see them. If they are wearing a bright orange life jacket you will be better able to see them than if their life jacket were blue or green.