What is 'aquaplaning' (hydroplaning) and how should you respond if it occurs on a wet road?

1. Tires lose contact with the road surface due to a layer of water; ease off the accelerator smoothly without harsh braking or steering
2. Water enters the engine; immediately apply the handbrake with maximum force
3. Brakes become wet; pump the accelerator repeatedly while turning the wheel sharply
4. The car begins floating; accelerate rapidly to push through the puddle