Jet sprint boat racing
Encyclopedia
Jetsprint or sprint boat racing is a form of racing
sport
in which jetboat
s with a crew of two race individually against the clock through 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 V8
s developing well over 500 hp.
s that had inspired Sir William Hamilton
to develop the jetboat
, but when the sport was introduced to Australia
in the mid-1980s permanent artificial courses were used—and this is now the norm even in New Zealand.
A fiercely contested Tasman
championship has now led to a three way world championship (with the introduction of the sport to the United States
, under the auspices of the Union Internationale Motonautique
). The host nation rotates between New Zealand, Australia and the U.S.A
s 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 sliding sideways across the water when turning at high speed.
A rollcage must be fitted to the boat.
Class A - Engines in Class A boats are restricted to either 6.7-litre (412 cubic inch) engines with cast iron
blocks and heads or 6-litre (365 cubic inch) engines with aluminium heads. Both size engines are only allowed two pushrod operated valves per cylinder. Furthermore the engine must be normally aspirated, using a 4-barrel carburettor. Fuel is 100+ octane aviation fuel
. Typically these engines produce up to 650 horsepower
Superboats - Engines in the superboat 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 inch) or while forced induction (turbocharged or supercharged) engines must be at least 3.8 litres (235 cubic inch) in displacement. These engines typically are fuel injected and run methanol
fuel. The small-block engines typically produce 950+ horsepower, while the big blocks can typically produce between 1000 to 1400 horsepower.
Nitromethane
and nitrous oxide
are not allowed.
Racing
A sport race is a competition of speed, against an objective criterion, usually a clock or to a specific point. The competitors in a race try to complete a given task in the shortest amount of time...
sport
Sport
A Sport is all forms of physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Sport may be competitive, where a winner or winners can be identified by objective means, and may require a degree...
in which jetboat
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 a propeller in the water below or behind the boat, a jetboat draws the water from under the boat into a pump inside the boat, then expels it through a nozzle at the...
s with a crew of two race individually against the clock through 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 V8
V8 engine
A V8 engine is a V engine with eight cylinders mounted on the crankcase in two banks of four cylinders, in most cases set at a right angle to each other but sometimes at a narrower angle, with all eight pistons driving a common crankshaft....
s developing well over 500 hp.
History
Jetsprinting as an organised sport originated in New Zealand in 1981, and events were originally held in the same natural braided riverBraided river
A braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...
s that had inspired Sir William Hamilton
Bill Hamilton (engineer)
Sir Charles William Feilden Hamilton , commonly known as Bill Hamilton, was a New Zealander who developed the modern jetboat, and founder of what is now the world's leading water jet manufacturing company - CWF Hamilton Ltd .Hamilton never claimed to have invented the jet boat. He once said "I do...
to develop the jetboat
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 a propeller in the water below or behind the boat, a jetboat draws the water from under the boat into a pump inside the boat, then expels it through a nozzle at the...
, but when the sport was introduced to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
in the mid-1980s permanent artificial courses were used—and this is now the norm even in New Zealand.
A fiercely contested Tasman
Tasman Sea
The Tasman Sea is the large body of water between Australia and New Zealand, approximately across. It extends 2,800 km from north to south. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European...
championship has now led to a three way world championship (with the introduction of the sport to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, under the auspices of the Union Internationale Motonautique
Union Internationale Motonautique
The Union Internationale Motonautique 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....
). The host nation rotates between New Zealand, Australia and the U.S.A
Format
The race itself will consist 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 8, then the top 4 and then the fastest two.Boats
A jetsprint hull is typically short - just 4 to 4.1 metres (13 to 13½ feet) long. The hull's vee is usually 23 to 25 degrees with several strakeStrake
A strake is part of the shell of the hull of a boat or ship which, in conjunction with the other strakes, keeps the sea out and the vessel afloat...
s 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 sliding sideways across the water when turning at high speed.
A rollcage 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 classesClass A - Engines in Class A boats are restricted to either 6.7-litre (412 cubic inch) engines with cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
blocks and heads or 6-litre (365 cubic inch) engines with aluminium heads. Both size engines are only allowed two pushrod operated valves per cylinder. Furthermore the engine must be normally aspirated, using a 4-barrel carburettor. Fuel is 100+ octane aviation fuel
Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...
. Typically these engines produce up to 650 horsepower
Superboats - Engines in the superboat 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 inch) or while forced induction (turbocharged or supercharged) engines must be at least 3.8 litres (235 cubic inch) in displacement. These engines typically are fuel injected and run methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
fuel. The small-block engines typically produce 950+ horsepower, while the big blocks can typically produce between 1000 to 1400 horsepower.
Nitromethane
Nitromethane
Nitromethane is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a slightly viscous, highly polar liquid commonly used as a solvent in a variety of industrial applications such as in extractions, as a reaction medium, and as a cleaning solvent...
and nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
are not allowed.