Jetsprint or sprint boat racing is a form of

motorboat racing Boat racing is a sport in which boats, or other types of watercraft, race on water. Boat racing powered by oars is recorded as having occurred in ancient Egypt, and it is likely that people have engaged in races involving boats and other wat ...

in which

jetboat A jetboat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses an external propeller in the water below or behind the boat, a jetboat draws the water from under the boat through ...

s, with a crew of two, race individually against the clock through a twisting series of channels in less than a metre of water. Tracks are typically designed for spectators, and racing is fast and loud, with boat motors usually powered by V8s developing well over 500 hp.

History

Jetsprinting as an organised sport originated in

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

in 1981, and events were originally held in the same natural

braided river A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment ...

s that had inspired Sir William Hamilton to develop the

, but when the sport was introduced to

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

in the mid-1980s, permanent artificial courses were used—and this is now the norm even in New Zealand. There is now a world championship under the auspices of the

Union Internationale Motonautique The Union Internationale Motonautique (UIM) is the international governing body of powerboating, based in the Principality of Monaco. It was founded in 1922, in Belgium, as the Union Internationale du Yachting Automobile. History Member nations ...

, with hosting rotating between New Zealand, Australia and the U.S.A.

Format

The race itself consists of a predefined course through the channels with 25 to 30 changes of direction. These races generally take just 45–60 seconds. Once qualifying is completed, the competitors each run the course with the fastest qualifiers running last. The fastest 16 (typically depending on the number of competitions) proceed to the next round. This is then reduced to the top 12, Top 8 then the top 5 and finally the fastest three.

Boats

A jetsprint hull is typically short - just 3.8 to 4.0 metres (12½ to 13 feet) long. The hull's vee is usually 23 to 25 degrees with several strakes on each side. A short hull is preferred, as a longer hull takes more distance to turn and usually must be turned at a slower speed. The strakes provide "traction' by stopping the boat from sliding sideways across the water when turning at high speed. A

rollcage A roll cage is a specially engineered and constructed frame built in (or sometimes around, in which case it is known as an exo cage) the passenger compartment of a vehicle to protect its occupants from being injured or killed in an accident, pa ...

must be fitted to the boat.

Crew

A crew consists of the driver and a navigator, whose responsibility is to guide the driver through the course - typically via simple hand signals, pointing the hand in the direction that the boat must go at the next intersection.

Classes

There are two internationally recognised classes Group A - engines in Group A boats are restricted to either 6.7-litre (412 cubic inch) engines with

cast iron Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuri ...

blocks and heads, or 6-litre (365 cubic inch) engines with aluminium heads. Both engines are only allowed two push-rod operated valves per cylinder. Furthermore, the engine must be normally aspirated, using a four-barrel carburetor. Fuel is 100+ octane

aviation fuel Aviation fuels are petroleum-based fuels, or petroleum and synthetic fuel blends, used to power aircraft. They have more stringent requirements than fuels used for ground use, such as heating and road transport, and contain additives to enhan ...

. Typically these engines produce up to 650 horsepower Super Boats - engines in the Super Boat class have no maximum size, but instead have a minimum size restriction. Normally aspirated engines must have a displacement of 6.5 litres (400 cubic inches), while forced induction (turbocharged or supercharged) engines must be at least 3.8 liters (235 cubic inches) in displacement. These engines typically are fuel injected and run

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is ...

fuel. The small-block engines typically produce 950+ horsepower, while the big blocks can produce between 1000 and 1600 horsepower.

Nitromethane Nitromethane, sometimes shortened to simply "nitro", is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a polar liquid commonly used as a solvent in a variety of industrial applications such as in ...

and

nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and ha ...

are not allowed.

External links

New Zealand Jetsprint AssociationAustralian V8 Superboats Jet Sprint ChampionshipJetsprint Legends online jet boat racingUnion Internationale MotonautiqueUSSBA Racing

References

{{Racing Motorboat racing