Fixit: Have an exit plan if car is submerged

Q In light of the bridge tragedy, I want to know what I should do if I end up in the water in the car? My car automatically locks when it's in drive, and the only way I can get the windows down is with the automatic power switch; there are no window cranks.

A You want to get out of your vehicle as quickly as possible if it's going to be submerged in water, said Lt. Mark Peterson of the Minnesota State Patrol. Try to open the doors to get out. If that doesn't work, try to lower the windows. Depending on the make of the car and the nature of the situation, that might not work, either. You may need to break the window to get out.

"It's not very hard to do," Peterson said. "I'd use an elbow or my feet." In a situation like that, don't worry about damage to the car, he added. Just break the window or windshield and get out.

Exiting the car isn't always the answer, however. Stay in your car if it's only going to be partially submerged, Peterson said. In situations with strong currents, including flash floods, you're better off staying with your vehicle, unless it appears that it will be completely submerged.

Finding yourself and your car suddenly in a body of water is very rare, Peterson said, except maybe for flash floods. Even that can be avoided in most cases by simply not driving through water.

"People think they can drive through water," Peterson said. But usually "the car will die and you will be stuck."

When that happens, you just have to sit and wait for emergency help, he said.

If you come upon water on a freeway, Peterson recommends pulling over onto the shoulder and waiting. Do not back up or turn around. That's dangerous and illegal. And, if it's more than a puddle, don't try to drive through it, even if you have all-wheel-drive or a sport-utility vehicle, Peterson advised.

Answering a similar question at Slate.com, Richard Martin of Survival Systems USA and J.A. (Doc) Watson advise:

If the car is sinking fast, wait for the interior to fill with water -- you won't be able to open the door until there's enough water inside the car to equalize the pressure on the outside. Opening the windows helps the water flow in faster, which gives you a better chance of escaping before your car sinks too deep. Survival experts recommend keeping your seat belt on until the last possible second. Otherwise, the rush of water could disorient and possibly injure you. Plus, it gives you extra leverage to open the door when it's time to escape. If for some reason you can't open the windows or doors, try kicking out the windshield or smashing a side window as a last resort. (You can buy emergency LifeHammers for just this purpose. They cost about $20 at www.lifehammersales.com.)

Try not to panic. Easier said than done, of course -- the impact of the water or an airbag probably will stun you. But it's hard to hold your breath if your heart is racing and carbon dioxide builds up in your blood too quickly. Survival Systems USA, a firm that trains soldiers in emergency escape techniques, has found that it takes about 20 seconds to escape through the door of a submerged car. A calm, relaxed person can hold their breath for 30 to 45 seconds underwater. So, if your pulse is pounding, you don't have much room for error.

When it comes to water exits, some cars are better than others. Lighter cars generally float longer, so you'd be better off in a Corolla than a Suburban. Even though an SUV has more space inside and therefore more air, its 6,000 pounds will pull it down faster.

An old Volkswagen ad campaign bragged about how a Beetle could float, but even the most buoyant cars won't stay above water longer than a minute or two. Float time also varies depending on how the car enters the water -- for example, an upside-down impact could break the windows -- and how tight the seal is on the doors. (Besides kicking tires, car buyers will often slam doors to test the seal. A good seal will produce a nice, crisp thwack.)

You're also better off with a car that has manual locks and windows instead of automatic ones. A car's electronics are likely to fail soon after it goes underwater, once its "brain boxes" -- small electronic modules that control the car's functions -- get wet. (These devices are often sealed against moisture, but are never waterproof.) Same goes for what's under the hood: Modern cars with electronic engine controls stop working when they get wet. That's why some cars can get stranded in the middle of deep puddles.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-9033, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. .