here is one girl's opinion...pretty funny.

To save life in case of emergency water landings.

The video is funny so I conclude that life jackets choke you to death. and they help you to find the dead body if sharks dont eat you up and one more piece of advise to ladies tie your hair up.

The surface of the earth is 70.6% covered in water..the chances are if your plane crashes...it will be in water

It's basically just for show. The airlines know this too. Although it does create a false sense of security for (some) passengers, the chances of surviving even a controlled crash landing in water are next to zero. Water takes on all the worst properties of concrete at speeds airplanes are likely to be traveling, hence references to, the search of the "wreckage field" on water for evidence of cause, rather than the search for large sections of intact fuselage with passengers inside arguing about whether they should eat Mrs Jones in 46-D next.

They are a historical relic. Back in the days when airplanes had propellers and piston engines, engine failure was much more common than it is today. So it was not ridiculous to think that the engines on an over water flight might fail and the plane come down in the water. The planes themselves were slower (so spending more hours over the sea), and flew lower (so having less ability to glide to safety) and closer to bad weather. So ditchings at sea were, while rare, not unknown, and it made sense to allow for them. Modern jet engines are much more reliable. No modern jet has *ever* ditched in the sea in a controlled manner in which these life jackets might be useful. But no-one is going to be the first to take *out* a safety device, no matter how obsolete, because if there *were* such an accident any time in the next thirty years, they would be crucified. Notwithstanding the fact that the money and weight could be much better spent on other safety measures. The best safety measure is training and lack of unnecessary pressure for both air and ground crew. But if you want to fit safety devices on the plane, the one thing that has happened several times in recent years is on-board fires, and particularly smoke. A cabin misting device, which could fill the cabin with a fine mist of water, settling smoke and maybe putting out the fire, would weigh less than all those life jackets, cost less, and would not be hard to fit - particularly from new. Of course, it would be set off accidentally some time, which would terrify passengers, damage the plane, and cause infinite lawsuits. But at other tiumes it would save lives.

duh!!

Because you can crash at any time. HELLO!!!

duh. because most likely if u crash, u will crash into---guess what. those big blue things covering most of the earth.

Contrary to common belief, and most notably the ignorant woman depicted in the above video, a water landing is a surviveable incident if its done correctly. Planes along coastal airports have ended up in the water for one reason or another over the years, and escaping the plane with a lifevest is a lot easier than swimming to shore. And for the woman in the video, I hope the next time a plane has to jettison some fuel, they do it at 1000 ft above her house.