'Twas brillig, and the slithy toves did gyre and gimble in the wabe

If the water is deep enough that you think it might cover your exhaust, low gear, high revs to stop water going up it and chocking the engine. Stalling in the middle of a lake sucks.

Second pro tip: you have a petrol car. Avoid deep water.

Third pro tip: remember drain covers can lift in flooded areas. They make for nice holes you can drop a wheel down. Avoid the edges (assuming you know where the road is). That said, if you can't find the road, see pro tip 2.