How To Drive Through Deep Water

Driving Through Deep Water

As you know, ICE engines draw in air, inject a small amount of fuel and then compresses it before igniting it. Air is a gas and gas can easily be compressed. Water on the other hand is a liquid and liquids cannot be compressed.

So if your air intake becomes a water intake, your engine draws in water and can’t compress. The engine comes to a sudden and destructive stop. Usually bending con rods or blowing out head gaskets.

This is called a hydrolock.

Watch A Bunch Of Clowns Doing It Wrong

What Did They Do Wrong?

They went far too fast in the water. The bow wave can be twice as deep as the standing water level. If the water level goes higher than the air inlet, your engine is dead. The important thing is to create a bow wave at the front of the car and not to overtake the wave. This reduces the height of the water behind the bow wave.

Going too fast will make the bow wave increase as you overtake it. Then your engine is dead.

Then the car stops moving and the water levels out.

Door seals aren’t design to hold back standing water so water will start to pour into the car. You’ll have a written off engine and a car written off by flood damage.

How Should It Be Done?

This is a video of me in my old 451. At the deepest point, the water is probably 12 inches (30cm) deep. We all got through fine but 1 car had already had hydrolock halfway through.

It’s all about keeping a nice slow consistent speed.

You Are Better Off With A Smart

You have 2 benefits in a smart. Firstly the engine is in the back. Secondly the air intake is quite high up. This doesn’t mean you can plough through the water like a moron though. Remember that the cabin air intake is still up front and you don’t want your air vents becoming water vents.

Notice how the height of the water behind the bow wave is below the door seals. This is perfect.

However, if you go too fast and try to go faster than the bow wave you have created, you create a 2nd wave.

If this travels to the back of the car and goes over the air intake, you have a dead engine.

As soon as that happens, the car stops moving, the water levels out and the interior starts to flood.

So, drive in slowly and keep a speed that keeps the bow wave in front of the car and not coming up the bonnet too far.

Caution

Knowing this and doing it properly doesn’t mean you’ll make it. Water can cause engine electrical issues. That can obviously cause the car to stall as well. If you can drive around the flood instead, do that.