A board ridden by a standing person and pulled by a motorboat for entertainment
For a car or similar vehicle to slide along the road on a thin film of water between the road and the tyres. This occurs when a car has some speed and comes to somewhere with more water on the road than the weight of the car and the grooves in the tyre tread pattern (if any) can push away. The result is almost no traction at all for steering or braking.
To ride such a board.