Boat racing
JetSprint powerboat racing
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JetSprint powerboat racing has been referred to as "Rally driving on Water".
Unlike most forms of powerboat racing, which take place on lakes, rivers, oceans, or other naturally occurring bodies of water, JetSprint boats race in narrow (4m wide), shallow (60cm deep), twisting channels created specifically for the race. They are appropriately called JetSprint "tracks". The races are run in an elimination format against the clock, one boat at a time. The boats with the best times advance to the next level, with the fastest survivors eventually in the finals.
The Origins of JetSprint
JetSprint racing traces it's origins to New Zealand and the inventor of the modern jet drive, Bill Hamilton. Bill Hamilton was a New Zealand sheep farmer who, in the early 1950's, decided to revitalize the concept of the water jet drive. Previously, a number of individuals as well as the governments of several countries had experimented with the jet drive propulsion system, to varying degrees of success. Usually, the standard propeller drive system was found to be more efficient, producing considerably more thrust with equivalent or less horsepower. Much of the inadequacy of previous jet drives was due to the inherent restriction of water flow due to the radial pumps being used in the drives.
Bill Hamilton, however, saw the advantages of jet drives as being important enough to devote considerable energy and resources to them. With no propeller to foul, jet powered boats can run in much shallower and extreme conditions than conventional boats.
Hamilton's greatest contribution to water jet propulsion was the development of the axial flow drive pump. This design eliminated much of the friction and flow restriction of the previous designs, and suddenly, jet drives were a fast, reliable, and extremely versatile method of powering a boat.
As with all forms of motor vehicles, if you build it, sooner or later, somebody will race it! New Zealand boaters with a need for speed quickly saw the appeal of this drive system, and found that when mated to a sufficiently large engine, and installed in a sturdy but lightweight boat, they could build a race boat unlike any other. From New Zealand, JetSprint racing quickly spread to Australia and other nearby areas. Eventually, it also has sprung up in the United States.
The Boats
JetSprint race boats are highly specialized craft, constructed of fibreglass or aluminum, and weigh between 450 to 600 kg. They are usually powered by automotive style 400 cubic inch V8 engines which, depending on class, produce over 500 hp. These 13 foot long boats can accelerate from 0 to 100 km/hr (60 mph) in 2.4 seconds, and can reach speeds of 140 km/hr in open water. Due to the scarcity of open water on a JetSprint track, a more realistic top speed is often around 100 km/hr.
The Teams
The crew of these powerful little boats consists of a driver and a navigator. They are held in by seat belts and are protected by a full roll cage. This is a necessity as spectacular flips, rolls, and spills are common. Unlike other forms of powerboat racing, these boats often end up upside down on dry (or muddy) land when they lose control. Due to the construction of the boats, however, serious injury to either crew or the boats is rare. For economic reasons (the cost of the boat), some boats have two crews, who race against each other at the same event. This is possible as the boats race one at a time, against the clock.