Enter the water crossing at a moderate speed. It risks drowning the electrical system, drawing water into the air-intake, and making a general mess of the car. The results can be very expensive if water is drawn into the engine air-intake. It has entered the water at a moderate speed, will accelerate gently building a bow-wave and get through without any drama. Always check the depth of water at an unknown crossing.
Clear water can be very deceptive - it is often deeper than it appears.
Muddy water can hide rocks and other obstacles as well as being just plain deep. Fit wading plugs to the housings for clutch, cam-shaft toothed belts, etc. as appropriate to your vehicle. Drape a tarpaulin over the radiator grille and tie it securely in place to reduce the amount of water entering the engine compartment. Move bedding and other gear to as high a position as possible. We tried to pull it out with a 1 ton dual wheel 4x4.