What is 'aquaplaning' (hydroplaning), and how should a driver respond if it occurs?

1. Tires lose contact with the road and slide on a thin film of water; ease off the accelerator and steer straight without braking
2. The engine stalls due to water entering the air intake; pump the brakes rapidly
3. The vehicle's brakes become wet and lose stopping power; apply heavy throttle to dry them
4. The windshield wipers fail during heavy rain; accelerate to clear the water by wind