If you are on the road and come across flood you will need to make a judgement based on the likely depth of the water and the type of vehicle you are driving. Just remember that if you decide to attempt to cross a flood, you are making a life or death decision. A standard family sedan will not be capable of driving through water and you are likely to encounter a variety of problems if you do.
-The water may prove to be too deep. An average sedan may float in water about 2ft deep. Be aware that it is often difficult to judge the depth of water in a flood.
-Water may enter the exhaust pipe (especially if the engine stalls)
-Water may be sucked into the engine air intake, which is often located close to the ground at the front of the car.
-Water may cause a catalytic converter to crack. This will be expensive to replace.
-Water may adversely affect the braking system. Brakes should be tested after emerging from a flood plain.
-Water inside the vehicle may cause short-circuits and set off the air bags.
If the decision has been made to drive through a flood, engage the vehicle in 1st gear and drive at a steady rate, without causing too much of a bow wave at the front of the vehicle.
If you attempt to drive at speed through standing water, even if it is relatively shallow, the car is likely to hydroplane and steering control will be lost.
Do not drive through a flooded area where there is fast-moving water
If the car is caught in a serious flood or driven into a river, lake or the sea, depending on the depth of the water you can:
-Abandon the vehicle and wade to safety.
-Climb on to the roof of the vehicle, exiting via an open window and signal for help.
-Make an emergency exit as detailed below.
If the car is totally immersed in water, the pressure inside and outside the vehicle will be uneven until the car interior has filled with water.
In this case it will be difficult to open a car door until the pressure has equalized. Also, any attempt to open a window will result in a heavy in-rush of water, which may prove severely disorientating and not give you time to catch your breath once submerged.
As the car is filling up with water, unfasten any restraints on yourself and any infants or children. You will need to get them out of car seats and into your lap or in the grasp of another adult. This will allow you to pull them from the vehicle as soon as exiting is possible. Before the car fills up with water, take a few deep breaths of air to fill your lungs and also to help reduce any possible inclination to panic. Take a final breath before your head is immersed and instruct any passengers to do the same. Infants and toddlers will naturally hold their breaths but only for very short periods. Expect to have to give mouth-to-mouth resuscitation to infants and toddlers when you exit the water. Remember to use cheek fulls of air for infants and mouth fulls for toddlers and not lung fulls as too much air will rupture their small lungs and kill them.
Next, energetically force open a door and signal to or grab (if visibility is limited)any others to exit that way. Once outside the vehicle swim to the surface, having checked that all other occupants are out.
If in high current waters, swim towards the shoreline or towards any solid objects such as trees by barrel rolling with the current going from front stroke to back stroke to front stroke, doing so will allow for a less exhausting swim.
If you are able to grab a hold of something that can be used as a flotation device do so, then wade through the water by kicking your feet. If capable, wrap your arms around the flotation device and hold-on till to come to a secure anchor such as a tree or some other structure.
If you are wearing a belt or still have your shoes on which have laces, you can attempt to secure yourself to your anchor if you are feeling weak or have been stuck there for some time. This will help ensure your arms or legs don't give out plunging you into the water. This will also allow you to sleep if need be. If so, you will be entering the possibility of immersion foot unless you are able to exit the water completely. Just be sure it can be adjusted for rising waters if you are not able to exit the waters.
**NOTE**
As a rule of thumb, when ever traveling near a large body of water, crack open your window. As soon as you hit the water, open your window. This is your best chance of escape, because opening the door will be nearly impossible given the outside water pressure. Opening the windows allows water to come in and equalize the pressure. If you are unable to do so, remain calm and wait for the pressure to equalize.
Vehicles with engines in the front will sink at a steep angle. If the water is 15 feet or deeper, the vehicle may end up on its roof, upside down. For this reason, you must get out as soon as possible, while the car is still afloat. Depending on the vehicle, floating time will range from a few seconds to a few minutes. The more airtight the car, the longer it floats. Air in the car will quickly be forced through the trunk and cab, and an air bubble is unlikely to remain once the car hits the bottom. So, get out as early as possible.