Grand National Hydroplane

The Grand National Hydroplane can travel at speeds in excess of 130mph. These boats barely touch the water as they glide across the surface throwing out a wall of water 20 feet high and up to 60 feet long called a rooster tail from a single two or three-bladed propeller at the rear of the boat. The sight of the rooster tail and the sound of the V8 motors roaring in your ears make the Grand National Hydroplanes one of the most exciting classes of boats to watch.

Class restrictions are as follows: 

There are no restrictions on boat size or weight. There are two types of hull design, Conventional and Cabover. In the conventional, the driver sits behind the motor, and in the cab over the driver sits in the front of the motor usually in a reinforced cockpit. Pump gas can be used to power the engines but most drivers usually prefer Aviation Fuel or Methanol.

Engine Restrictions:

Up to 4.2ltrs can be fitted with Carburetion, Fuel injection, turbo or supercharger. Aluminium blocks and heads permitted. Over 4.2ltrs up to and including 6ltr engines can be fitted with Carburetion or Injection only. Aluminium blocks and heads permitted. Over 6ltrs up to and including 7.7ltr can be fitted with one single Carburettor only. Aluminium heads permitted but the block must be a cast iron type.

Kilo Speed Records

New Zealand GNH Champions