What is Life vest?
[[Image:Life vest.jpg|thumb|A man wearing a red life vest.]] [[File:USS HARPERS FERRY (LSD 49) 131116-N-TQ272-505 (10943238764).jpg|thumb|Members of the US Navy, wearing life vests. ]] [[File:Two French bulldogs swimming in life jackets.jpg|thumb|Life vests for [[Dog|dogs]]: Two [[French Bulldog|French bulldogs]] swimming with life vests. This kind of dog breed can't hold its head above the water, so it needs a life vest.]] [[File:Lifejacket Instructions.jpg|thumb|Instructions how to use a life vest, on a Greek [[ferry]]. ]] [[File:Rettungsweste 275N.jpg|thumb|Highest category life vest, providid a flotation of 275 Newton. This is the kind used in vessels at high seas: It will be able to support an unconscious adult sailor, in heavy gear. ]] A '''life vest''' (also called '''personal flotation device''', '''lifejacket''', or '''cork jacket''') is a special type of [[clothing]]. The [[wikt:vest|vest]] makes people float in water. It also keeps their head out of the water so that they can breathe. There are different categories of life vests. They are mainly different in how much flotation they provide. Some life vests [[wikt:inflate|inflate]] all by themselves, others need to be filled with air manually. A life vest has one very important property: The part of keeping the head outside the water works even if the persion is [[Unconsciousness|unconscious]], or unable to do anything. A [[swimming aid]] will simply help the person in the water, and make swimming easier. It will not work on its own. People doing [[Water sports|watersports]], for example sailing, usually wear life vests. == Types == There are two broad categories of life vests: * Those that are worn all the time, sometimes over clothing. Here, the design goal is also that wearing them is moderately comfortable. Example users are sailors, and people doing certain water sports. This use is called preventative. * Those that are only worn on occasion: For example, those on planes, or on passenger ferrries. Usuallly they are designed so that the