Hydroplaning or aquaplaning by a road vehicle occurs when a layer of water builds between the rubber tires of the vehicle and the road surface, leading to the loss of traction and thus preventing the vehicle from responding to control inputs such as steering, braking or accelerating. It becomes, in effect, an unpowered and unsteered sled.
		In Florida - the rains are heavy, and they come quickly.
		In a half hours time the weather can go from sunshine,
		to heavy rain, and back to sunshine again.
		This is known as Florida Ice. 

Every vehicle function that changes direction or speed, from turning, to accelerating, to braking, places an increased load on the tires. Control of this load relies on the friction between the tire contact points and the road surface. More friction makes for a greater resistance to slipping; if water comes between the tires and the road, friction may be reduced to the extent that the driver may lose control.The tread or grooves, sometimes referred to as sipes, of a rubber tire are designed to remove water from beneath the tire, providing high friction with the road surface even in wet conditions. Hydroplaning occurs when a tire encounters more water than it can dissipate. Water pressure in front of the wheel forces a wedge of water under the leading edge of the tire, causing it to lift from the road. The tire then skates on a sheet of water with little, if any, direct road contact, resulting in loss of control.

If multiple tires hydroplane, the vehicle may lose directional control and slide until it either collides with an obstacle, or slows enough that one or more tires contact the road again and friction is regained.

The likelihood of hydroplaning increases with the speed of the vehicle and the depth of the water. Tread wear and underinflation also increase the risk for hydroplaning, as do wider tires. Narrower tires are less vulnerable to hydroplaning because the vehicle weight is distributed over a smaller rubber contact patch, resulting in a greater ability for the tires to press water to the sides, allowing tire contact with pavement.

The practice of plus sizing by replacing a vehicle's original equipment wheel size with a larger diameter wheel and replacing the tire with a lower-aspect-ratio tire of the same diameter affects, some of the performance characteristics of vehicles, as well as increases the risk of hydroplaning with the wider tires.

Bicycles, motorcycles, and similar vehicles with a round-shaped surface toward the pavement are far less likely to hydroplane in normal road use. The contact area with the road is a canoe-shaped patch that effectively squeezes water out of the way. However, because road friction is reduced in wet conditions, the lateral force that the tires can accommodate before sliding is greatly diminished. While a slide in a four-wheeled vehicle is correctable with practice, the same slide on a motorcycle will generally cause the rider to fall, with severe consequences. Thus, despite the relative lack of hydroplaning danger, motorcycle riders must be even more cautious because overall traction is reduced by wet roadways.