DISPLACEMENTS
These boats are probably the easiest to relate to for the public. Displacements are, from a distance, the closest resemblance to your average water ski boat, with the engine mounted “inboard”, usually at the rear of the boat.
Obviously these finely tuned racing boats are a little different than your average ski boat. Construction materials range from fibreglass & plywood through to high-tech materials like kevlar and carbon fibre, making these craft very light and very strong in relation to your average ski boat.
The term "displacement" is derived from the action of the boat "displacing" (pushing water out of the way) the water as it moves through the water. Displacement hulls have no steps, recesses or tunnels more than approx. 35mm deep.
Displacements classes range from 3.4 litre skiffs all the way up to the monstrous Blown Alcohol Displacements.
Unlimited means unlimited, but must remain of an automotive configuration.
Blown means supercharged, turbocharged, or any other means of forced induction.
Limited eg: 6 litre, 5.2 litre, 4.2 litre etc means the volume of the motor is not more than the stated limitation.
HYDROPLANES
Hydroplanes are designed to ride on a cushion of air. The sponsons on either side of the boat create an air trap under the main portion of the boat.
As the air is trapped under the boat, the resulting pressure effectively lifts the boat out of the water, causing the boat to ‘plane ‘on the top of the water. These styles of boats are very spectacular to watch as they dance over the waves.
Hydroplane classes range from 1.6litre restricted up to supercharged Grand Prix Hydroplanes. The hull has steps, recesses or tunnels more than approx 35mm deep.
