What are the chances of your car window shattering and the pressure from the inflow of water of seriously hurting you or killing you? Seems to me, if you were submerged and busted the window, all of that glass would be coming right at your face…
Why can’t people just roll down the window… or why don’t they ever think of it?
I think you do want to let the water level equilibrate a bit but if you wait too late it’s going to be difficult to swing at it unrestricted. Rolling down the window would likely be best but many if not most cars nowadays have electric windows, hence the need for a hammer (metal tool).
Also, I’d imagine one at risk of drowning had best consider the potential depth they might reach. If my car’s going to sink way deep then I’m grabbing any opportunity to get out way early.
In many newer cars it is impossble to “roll down the window” The windows are controlled electrically and being completely underwater is generally bad for a car’s electrical system.
An alternative to breaking the window is to wait until the car has partially filled with water, then open the door.
I guess the reason we might have heard for letting the water equilibrate would be to open the door easier. However, there’s a good chance that still wouldn’t be possible and this link, as well as others, advocates getting out as soon as possible.
I carry a hammer made for this purpose in my glove box and it’s got a seat belt cutter on it as well. You also never know when you might need to free someone else involved in a wreck you’ve just observed, particularly if they’re unconscious, so it’s a good tool for everyone to have available.
[QUOTE=smootman]
all of that glass would be coming right at your face…/QUOTE]
The glass is not inherently dangerous. Car windows are made of “safety glass” that breaks into little cubes rather than shards. It would comparable to being hit in the face with a shovelful of rock salt.
I drive my Yugo wearing SCUBA gear and a speargun at my side. Looks funny as hell, but I’ll be damned if I go the way of the Titanic.
Also, I believe the rear windows of many cars are designed to be kicked out should just such a scenario occur. Sorry, no cite for that.
It’s awfully difficult to open a submerged car door until the car itself is totally filled up with water. The trick is: a) not to panic and b) wait until the car is totally filled with water, and open the door. Even then, the door will open rather slowly, but it will open. Also, you can swim out the window if you’ve got it totally open and aren’t too big.
There is an submerged car safety class in the Netherlands which lets you test the theory in practice.
As for the OP’s question as to why people don’t think about opening their windows…umm…if you’re not prepared for the situation, you panic and forget.
remember pop.
pop the seat belt
open an exit
push out
the hammer and belt cutter thingy is a very good tool to have. sometimes things get twisted up and bent around during accidents.
Well, as for me, I’d much rather wait for a car equipped with an ejection seat/parachute. Hmm better have a life raft with me as well in case my car falls into the ocean and I get stranded 
According to an article I read somewhere, many (possibly most) drownings in submerged cars are due to people remembering all of the advice about opening a window and letting the car fill up, but forgetting to remove their seatbelt (this data being gathered from people’s experiences in training, and the frequent discovery that uninjured drowned people in cars were still belted in.
I’d imagine that those little safety hammers are a bit hard to swing effectively underwater, so I think I’d be reluctant to wait for the car to fill before hitting the glass, if I was relying on exiting from a window.
Did you pick that up from The Stunt Man? 
“Don’t worry. It’ll be there.”
There is some sort of ‘adhesion’ process going on with auto glass, especially the windshield. It is not going to shatter and disappear after being struck. I’ve done forcible entry into autos on dry land, and it takes more than one smack with a forcible entry tool before you can make uninhibited entry. I’ve seen entire windshields intact, but in thousands of pieces of glass still connected as a whole window.
That may be true, but with the pressure of the water behind it, I think it would probably be pushed in, even if the car is only a few feet underwater.
It’s a bit hard to roll down the window with the huge amount of pressure the water is pressing against your window.
And supposing you’re underwater in a car, I figure a few cuts from bits of safety glass is one hell of a lot better than drowning. I doubt the glass will be of large enough size to do any significant damage to you.
Ho boy,
Ah, no. The window rolls down, not out. The water pressure will not be a problem.
The term is lamination. The windshield (and sometimes the side windows) are laminated. A thin plastic sheet is laminated between two pieces of glass. This is to prevent passengers from being thrown from the car in an accident. There is no way you are going to knock out a windshield while under water. Too much work, too little oxygen. Some high end new cars also have laminated side windows. This is to prevent theves from breaking a window and stealing stuff from inside the car. If you have laminated side windows, forget about breaking them out in a sinking car. Not going to happen. If you are not sure about the windows on your car, roll down the side window a few inches. If the window is standard tempered glass the top of the window will be smooth. If you have laminated windows, there will be a sandwich both visible and to the touch. Glass on both sides, plastic in the middle.
If there are such windows, I have never come across any reference to them in over 30 years in the automotive business. Also if you do the math you can probably figure out that even AREnold would have a problem kicking out a window. Let’s see a rear window 2’ X 5’= 10 square feet. 1 square foot =144 square inches. 10 X 144 = 1,440 square inches. If there is only a one pound per square inch pressure differental between the inside and the outside you would have to press with 1,400 pounds of presure to move that window. Good Luck.
You might want to verify that this sucker will do what you think it will do. A friend of mine is in the mail order auto accessory business. They decided to road test one of the these hammers before selling it. They could not break a window while on dry land. They did not add this item to their catalog. YMMV of course.
From the folks at Worst Case Scenarios…
http://www.worstcasescenarios.com/scenario.htm?scenarioid=3&cache=1079400045
There was a survival show on Discovery last year that covered this. According to them, you should be able to kick out any window in your car except for the front windshield. Although RICK’S post sheds doubt on that for some cars.
They also said that generally your electrical system WILL work when submerged for a while. Apparently it’s normal for the system to continue working for at least 15 minutes after fully submerged, and in rare cases rescue divers have noticed headlights still operational after a couple of hours of being submerged.
In other words, there will almost certainly be enough juice left to electronically lower the windows before the car fills with water.
No electronic sites I can link to, but it was definitely on the Discovery Channel. Sorry that’s all I have.
Anecdotal evidence: My uncle punched through a passenger side window, breaking the driver’s jaw in one blow. He intentionally rammed my uncle with his car. If you are strong it is quite possible on dry land, I dunno about water.
Almost all cars have tempered (‘safety’) glass in the side windows. The nature of tempered glass allows it to be easily broken with the right tool. All you need is a hard pointy object. Just push on the glass with the hard point, and the entire window will shatter. You should not need to get a good swing.
This is due to the way tempered glass is made. Basically, the outer surface of the glass is under high compression, and the inside is under high tension. As such, any imperfection that is introduced will cause a catastrophic failure of the entire window, breaking the entire window into itty bitty pieces that are not large enough to cause serious injury.
Here’s a link that has a bit of information on tempered glass: GlassResource.com is for sale | HugeDomains
Also, most cars that I have seen have a little logo painted on the windows that indicates what type of glass the window is made of.