If you have to drive through a flood, keep the engine revs up to stop water entering the exhaust pipe. Too much speed will create a bow wave which could flood the engine, but you'll need a stab of extra throttle if you are leaving a ford by a bank.
Apply the brakes to dry them when you get out of the water - this can take some time with drums.
The assumption that the good grip of modern tyres means you are always safe on wet roads in a...