Jetboat
Overview
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 stern
.
Jetboats were originally designed by Sir William Hamilton
(who developed a waterjet in 1954) for operation in the fast-flowing and shallow rivers of New Zealand
, specifically to overcome the problem of propellers striking rocks in such waters.
Previous attempts at waterjet propulsion had very short lifetimes, generally due to the inefficient design of the units and the fact that they offered few advantages over conventional propellers.
Boat
A boat is a watercraft of any size designed to float or plane, to provide passage across water. Usually this water will be inland or in protected coastal areas. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In naval terms, a boat is a...
propelled by a jet of water ejected from the back of the craft. Unlike a powerboat
Powerboat
A powerboat is another name for a motorboat. Powerboat may also refer to:* Powerboating* F1 Powerboat World Championship* Offshore powerboat racing...
or motorboat
Motorboat
A motorboat is a boat which is powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the gearbox and the propeller in one portable unit.An inboard/outboard contains a hybrid of a...
that uses a propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
in the water below or behind the boat, a jetboat draws the water from under the boat into a pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
inside the boat, then expels it through a nozzle at the stern
Stern
The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...
.
Jetboats were originally designed by 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...
(who developed a waterjet in 1954) for operation in the fast-flowing and shallow rivers of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, specifically to overcome the problem of propellers striking rocks in such waters.
Previous attempts at waterjet propulsion had very short lifetimes, generally due to the inefficient design of the units and the fact that they offered few advantages over conventional propellers.
Discussions
