A personal watercraft (PWC), also called water scooter or jet ski, is a
recreation
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...
al
watercraft
Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail, ...
that a rider sits or stands on, not within, as in a
boat
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats.
Small boats are typically found on inl ...
. PWCs have two style categories, first and most popular being a runabout or "sit down" where the rider uses the watercraft mainly sitting down, and the watercraft typically holds two or more people. The second style is a "stand-up", where the rider uses the watercraft standing up. The stand-up styles are built for one rider and are used more for doing tricks, racing, and use in competitions. Both styles have an
inboard
An inboard motor is a marine propulsion system for boats. As opposed to an outboard motor where an engine is mounted outside the hull of the craft, an ''inboard motor'' is an engine enclosed within the hull of the boat, usually connected to a pr ...
engine driving a
pump-jet
A pump-jet, hydrojet, or water jet is a marine system that produces a jet of water for propulsion. The mechanical arrangement may be a ducted propeller ( axial-flow pump), a centrifugal pump, or a mixed flow pump which is a combination of bot ...
that has a screw-shaped
impeller
An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid.
In pumps
An impeller is a rotating component ...
to create thrust for propulsion and steering. Most are designed for two or three people, though four-passenger models exist. Many of today's models are built for more extended use and have the fuel capacity to make long cruises, in some cases even beyond 100 miles (161 km).
Personal watercraft are often referred by the
trademark
A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from others ...
ed brand names of personal watercraft by
Kawasaki (
Jet Ski
Jet Ski is the brand name of a personal watercraft (PWC) manufactured by Kawasaki, a Japanese company. The term is often used generically to refer to any type of personal watercraft used mainly for recreation, and it is also used as a verb to ...
),
Yamaha Yamaha may refer to:
* Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below).
** Yamaha Music Foundation, an organization estab ...
(
WaveRunner
WaveRunner is a trademarked name and type of personal water craft (PWC) produced by the Yamaha Motor Company. Unique to the WaveRunner among PWCs is the spout of water that shoots into the air from the rear of the vehicle, a visual brand identif ...
),
Bombardier (
Sea-Doo
Sea-Doo is a Canadian brand of personal watercraft (PWC) and boats manufactured by Bombardier Recreational Products (BRP). All Sea-Doo models are driven by an impeller-driven waterjet. All Sea-Doo PWC models are currently produced at BRP's plants ...
) and
Honda
is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan.
Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...
(AquaTrax).
The
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mult ...
defines a personal watercraft, amongst other criteria, as a jet-drive boat less than 13 feet (4 m) long. There are many larger "
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" not classed as PWCs, some more than 40 feet (12 m) long.
History
Water scooters—as they were originally termed—were first developed in the United Kingdom and Europe in the mid-1950s, with models such as the British 200cc propeller-driven
Vincent
Vincent ( la, Vincentius) is a male given name derived from the Roman name Vincentius, which is derived from the Latin word (''to conquer'').
People with the given name Artists
*Vincent Apap (1909–2003), Maltese sculptor
*Vincent van Gogh ...
''Amanda'', and the German ''Wave Roller''. Two thousand Vincent Amandas were exported to Australia, Asia, Europe and the United States.
The Sea Skimmer was introduced in 1961 as a highly maneuverable version of a propelled surfboard. It was 5 feet 6” long, powered by an inboard/outboard motor and reached speeds up to 25 MPH. The rider lay on the boat, controlling the speed with hand throttles and using the feet as rudders. Originally manufactured in Kansas City, operations moved to Boynton, Florida in 1962, and changed the name to Aqua-Skimmer. Aqua-Skimmer ceased operations in 1962 and sold its inventory to the military. Renamed Aqua Dart (Aqua Dart INC), the
Sea Skimmer, Aqua Skimmer, Aqua Dart
The Sea Skimmer was a leisure Personal Watercraft (PWC) unique within the family of Personal Watercraft, whereas the operator laid prone on the boat and steered with shifting leg motions and body weight to control the craft, reaching speeds up to ...
was modified for military requirements, and saw service in 1962 river reconnaissance missions in Vietnam and other military missions until the 1970s.
In the 1960s, the idea was developed further by
Clayton Jacobson II
Clayton Jacobson II (October 12, 1933 – August 18, 2022) was an American inventor who was credited with inventing the jet ski.
Biography
Early life
Jacobson was born in Multnomah County Hospital, Portland, Oregon, on October 12, 1933, to Cl ...
of
Lake Havasu City, Arizona
Lake Havasu City (, ) is a city in Mohave County, Arizona, United States. As of the 2020 census, the population of the city was 57,144, up from 52,527 in 2010. It is served by Lake Havasu City Airport.
History
The community first started as an ...
, USA. Originally a motocross enthusiast,
Jacobson's idea was designed in the mid-1960s, powered by an internal
pump-jet
A pump-jet, hydrojet, or water jet is a marine system that produces a jet of water for propulsion. The mechanical arrangement may be a ducted propeller ( axial-flow pump), a centrifugal pump, or a mixed flow pump which is a combination of bot ...
rather than an
outboard motor
An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method ...
,
made of all aluminum, and had a fixed, upright handle. Jacobson eventually quit his job in banking to devote himself to developing the idea, and had a working prototype by 1965. It differed slightly from modern personal watercraft but had definite similarities. He completed a second prototype a year later made of fiberglass.
The first Clayton-type PWC to reach the market was designed by
Bombardier in the late 1960s. Bombardier's original designs were not very popular and Bombardier left the business before 1970.
In Greece, an inventor named Dimitrios T. Moraitidis, built a prototype an
submitted a patent to the government of the Kingdom of Greece with serial number, on the 5th June 1970, with serial number 40056 He never exploited the invention commercially. He passed away on Mar 5 2022.
Stand-up PWCs were first produced by the Japanese company
Kawasaki (under the
Jet Ski
Jet Ski is the brand name of a personal watercraft (PWC) manufactured by Kawasaki, a Japanese company. The term is often used generically to refer to any type of personal watercraft used mainly for recreation, and it is also used as a verb to ...
brand) in 1972, and appeared on the US market in 1973. These were mass-produced boats to be used by only one rider. While they are still produced today, the more popular design is the sit down variety of PWC. These sit down runabouts have been produced by Kawasaki (Jetski), Bombardier (
Sea-Doo
Sea-Doo is a Canadian brand of personal watercraft (PWC) and boats manufactured by Bombardier Recreational Products (BRP). All Sea-Doo models are driven by an impeller-driven waterjet. All Sea-Doo PWC models are currently produced at BRP's plants ...
), Yamaha (
WaveRunner
WaveRunner is a trademarked name and type of personal water craft (PWC) produced by the Yamaha Motor Company. Unique to the WaveRunner among PWCs is the spout of water that shoots into the air from the rear of the vehicle, a visual brand identif ...
),
Honda
is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan.
Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...
(AquaTrax),
Polaris (Sealion) and
Arctic Cat
Arctic Cat is an American brand of snowmobiles and all-terrain vehicles manufactured in Thief River Falls, Minnesota. The company was formed in 1960 and is now part of Textron Inc. Arctic Cat designs, engineers, manufactures and markets all-terr ...
(
Tigershark
The tiger shark (''Galeocerdo cuvier'') is a species of requiem shark and the last extant member of the family Galeocerdonidae. It is a large macropredator, capable of attaining a length over . Populations are found in many tropical and tempera ...
). As of 2010, the major manufacturers of PWCs were Kawasaki, Bombardier and Yamaha. Both Yamaha and Kawasaki continue to sell stand-up models but it is a small percentage of the overall market.
Sports
PWC racing competitions take place around the world. There are several disciplines: closed circuit speed races, offshore speed races (offshore), endurance races, freestyle (freestyle) and freeride events. For all these types of events, with the exception of freestyle, there are at least two categories: saddle jets and stand-up jets. For speed races, gear is generally classified according to the degree of authorized modifications: minor modifications fall into the so-called "stock" category, intermediate modifications into the so-called "limited" category, and more extensive modifications into the category. known as "F1". In freestyle and freeride, these categories do not exist, we classify the competitors according to the type of watercraft used (with stand-up or saddle).
The sport is ruled by the World Powerboating Federation (
U.I.M.) recognised by the
IOC
The International Olympic Committee (IOC; french: link=no, Comité international olympique, ''CIO'') is a non-governmental sports organisation based in Lausanne, Switzerland. It is constituted in the form of an association under the Swiss ...
. The current official world series that was established in 1996 is the
Aquabike World Championship. The sport is also established at national level and is ruled by each national federations member of the
U.I.M.
Aquabike World Championship is known among the motorsports with most different national entries for each competition, reaching up to 32 nationalities and 140 riders registered to compete in
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...
in 2018.
Other private competitions also exists such as P1 AquaX which is a personal watercraft racing series, first launched in the UK in May 2011 by London-based sports promoter Powerboat P1. The series attracted a mix of new and current racers to a new type of racing and in 2013, P1 rolled out a second series in the USA. Such was the uptake that the original format needed revising to cope with the influx of new riders and by the end of 2015 over 400 riders from 11 countries had registered to compete in an AquaX event.
In the United States, the main sanctioning bodies are the International Jet Sport Boating Association (IJSBA) and Pro Watercross (PWX). As of 2022, the sport is experiencing exceeding levels of fragmentation and conflict due to poor management of the sanctioning bodies and non-constructive competition between organizations. The IJSBA World Finals competition is traditionally held in Lake Havasu City, Arizona in early October. The Pro Watercross World Finals are typically held in Naples, Florida in November.
Non-recreational uses
PWCs are small, fast, easily handled, fairly easy to use, and affordable, and their propulsion systems do not have external propellers, making them in some respects safer than small motorboats for swimmers and wildlife. For these reasons, they are used for
fishing
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...
, one of the PWC industry's fastest-growing segments.
Lifeguards use PWCs equipped with rescue platforms to rescue water users from trouble, as well as flood survivors, and carry them to safety. Police and rangers use them to enforce laws in coastal waters, lakes and rivers. A PWC combined with a wash-reduction system, carrying waterproof loudspeaker equipment and GPS for instructions and distance measurement, has reportedly been used by assistant coaches for rowing sports on the River Tyne.
Further, PWCs are used by the U.S. Navy as surface targets. When equipped with GPS, electronic compass, radar reflector, and a radio modem, the PWC can be controlled remotely with a two-way link. Its small shipboard footprint allows it to be stored in and deployed from the smallest of vessels, and it has been used for target practice for armaments of sizes from
cannon
A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder ...
to
small arms
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions).
The first firearms originated in 10th-century China, when bamboo tubes c ...
.
Emissions
The American PWC industry reached an agreement with the United States Coast Guard in 1999 (see fall, 1999 BSAC Minutes), agreeing to limit the speed of a PWC to 65 mph in a specified test protocol.
Before 1991, PWC emissions were unregulated in the United States. Many were powered by
two-stroke cycle
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...
engines, which are smaller and lighter than
four-stroke cycle
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directi ...
engines but more polluting. Simple two-stroke engines are lubricated on a "total loss" method, mixing lubricating oil with their fuel; they are estimated to create exhaust in excess of 25% of their fuel and oil unburned in addition to the products of incomplete and complete combustion.
The 1990 amendments to the
Clean Air Act allowed the
U.S. Environmental Protection Agency
The Environmental Protection Agency (EPA) is an Independent agencies of the United States government, independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon pro ...
to begin regulating all recreational marine engines including PWC, as well as other off-road
internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...
s. The agency began a dialogue with manufacturers in 1991, resulting in regulations that were enacted in 1996. These regulations, set to phase in between 1998 and 2006, are considered averaging standards, because they allow manufacturers to offset more-polluting engines in their product range by offering other engines that exceed the standard. California and subsequently New York have, in turn, adopted more stringent regulations than the federal standard. Subsequent to 2004 when the maximum emission reductions required by California became effective, the substantial majority of new PWC units sold throughout the United States have met the lower emissions standards established by California.
To meet these regulations, manufacturers have adopted a variety of improvements, including increased use of four-stroke engines, the use of direct injection for two-strokes, and the use of
catalytic converter
A catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. Catalytic converters are usually ...
s and other pollution-curbing measures that overall have reduced emissions by approximately 75% compared to pre-regulation models.
In some areas, such as
Lake Tahoe
Lake Tahoe (; was, Dáʔaw, meaning "the lake") is a Fresh water, freshwater lake in the Sierra Nevada (U.S.), Sierra Nevada of the United States. Lying at , it straddles the state line between California and Nevada, west of Carson City, Nevad ...
, outboard motors and PWCs are permitted if they meet the 2006 EPA or California Air Resources Board (CARB) 2001 regulations. Some pre-2006 model year PWCs meet this EPA standard, including all four-stroke makes and models and all
two-stroke cycle
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...
direct-injection (non-carbureted) models.
Environmental groups such as the
Surfrider Foundation
The Surfrider Foundation USA is a U.S. 501(c)(3) grassroots non-profit environmental organization that works to protect and preserve the world's oceans, waves and beaches. It focuses on water quality, beach access, beach and surf spot preservati ...
and the
Bluewater Network claim that more rapid progress could be made, and that the diminishing numbers of pre-1998 watercraft in use continue to emit substantial pollution.
Against this, industry groups such as the
Personal Watercraft Industry Association
{{more citations needed, date=December 2021
The Personal Watercraft Industry Association (PWIA) is an American association of personal watercraft (PWC) manufacturers. It is an affiliate of the larger National Marine Manufacturers Association, an ...
point out that environmental groups continue to cite pollution levels of pre-regulation watercraft and ignore the improvements made to newer models; and furthermore, that personal watercraft are unfairly singled out when they are no more polluting than other powered boats.
File:Yamaha SUV.jpg, Some personal watercraft carry as many as four passengers, contain up to engines
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power g ...
, reach speeds of up to , carry of fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
, and feature amenities such as sun pads and extra padded cruising seats.
File:Sea Doo LRV.JPG, Even the largest PWC, the Sea-Doo
Sea-Doo is a Canadian brand of personal watercraft (PWC) and boats manufactured by Bombardier Recreational Products (BRP). All Sea-Doo models are driven by an impeller-driven waterjet. All Sea-Doo PWC models are currently produced at BRP's plants ...
LRV, can be easily loaded onto a trailer and transported from one body of water to another.
Hazards
Apart from the obvious hazards of collisions and mechanical breakdowns common to all
vehicle
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wa ...
s, operating or riding a PWC can involve a risk of
orifice
An orifice is any opening, mouth, hole or vent, as in a pipe, a plate, or a body
* Body orifice, any opening in the body of a human or animal
*Orifice plate, a restriction used to measure flow or to control pressure or flow, sometimes given specia ...
injuries. These injuries are typical of the kinds of injuries that waterskiers experience as a result of falling into the water at speed. Such injuries can occur from simply falling in the water at speed or they can occur from the output end of the pump jet. A rider who falls (or is ejected) off the back can land directly in the path of the PWC's high-pressure jet of water. Unless a rider is appropriately dressed in garments made out of a strong, thick substance like
neoprene
Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene.Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion R ...
(as is commonly found in
wetsuit
A wetsuit is a garment worn to provide thermal protection while wet. It is usually made of foamed neoprene, and is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports and other activities in or on water. It ...
s), the jet may penetrate any orifice it reaches. All major PWC manufacturers warn about this risk and recommend that passengers wear wet suit bottoms or equivalent protection. The American Waterski Racing Association recommends that all of their racers wear wet suit bottoms for this same reason.
Such orifice injuries can result in permanent disability or death. For example, in 2006, the
California Court of Appeal
The California Courts of Appeal are the state intermediate appellate courts in the U.S. state of California. The state is geographically divided along county lines into six appellate districts. for the First Appellate District upheld a $3.7 million
Napa County
Napa County () is a county north of San Pablo Bay located in the northern portion of the U.S. state of California. As of the 2020 census, the population was 138,019. The county seat is the City of Napa. Napa County was one of the original c ...
jury verdict against
Polaris Industries
Polaris Inc. is an American automotive manufacturer of RZR, motorcycles, snowmobiles, all-terrain vehicles, and neighborhood electric vehicles headquartered in Medina, Minnesota, United States. Polaris was founded in Roseau, Minnesota, where ...
arising out of one such incident (which had devastating effects on the victim's lower abdomen).
It is also possible for multiple riders on the same PWC to sustain orifice injuries in a single accident, as actually occurred in a 2007 accident at
Mission Bay which resulted in a
San Diego County
San Diego County (), officially the County of San Diego, is a county in the southwestern corner of the U.S. state of California. As of the 2020 census, the population was 3,298,634, making it California's second-most populous county and the fi ...
jury verdict affirmed in full on appeal in 2014.
[''Colombo v. BRP US Inc.''](_blank)
230 Cal. App. 4th 1442; 179 Cal. Rptr. 3d 580 (2014). As the appellate court explained in its opinion, this case was delayed after the PWC owner initiated a proceeding in federal court under the Limitation of Liability Act of 1851.
Another noteworthy risk of injury is known as off throttle steering which results from the lack of steering capability while off throttle in certain model PWC this can result in death or serious bodily injuries.
While also rare, spinal injuries can occur while surf jumping and, potentially, wake jumping. The PWC manufacturers owner's manuals all include warnings regarding jumping at excessive heights, or operating a PWC if there is a prior history of back injury. The current on-product labels say "Jumping wakes or waves can increase the risk of spinal/backbone injuries (paralysis)". The current Kawasaki owner's manual provides: "Slow down before crossing waves. Do not ride if you have a back condition. High speed operation in choppy or rough water may cause back injuries."
Another rare, but unique injury risk with jetboats, is being sucked into the intake side of the pump jet. Current PWC products contain on-product warnings that state: "''Keep away from Intake Grate'' while the engine is on. Items such as long hair, loose clothing, or PFD straps can become entangled in moving parts and result in severe injury or drowning".
There have been fatal accidents involving PWCs. In a notable case, U.S. astronaut
Alan G. Poindexter
Alan Goodwin "Dex" Poindexter (November 5, 1961 – July 1, 2012) was an American naval officer and a NASA astronaut. Poindexter was selected in the 1998 NASA Group (G17) and went into orbit aboard Space Shuttle missions STS-122 and ST ...
died in 2012 from injuries sustained in a Jet Ski accident in
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
.
See also
*
Aqua scooter (of historical interest)
*
Flyboard
A Flyboard is a brand of hydroflighting device which supplies propulsion to drive the Flyboard into the air to perform a sport known as hydroflying.ExamplesFlyboard Ultimate SupercutPower Board Expert.
A Flyboard rider stands on a board connec ...
*
Video games
Video games, also known as computer games, are electronic games that involves interaction with a user interface or input device such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device to gener ...
featuring personal watercraft:
** ''
Jet X2O''
** ''
Splashdown
Splashdown is the method of landing a spacecraft by parachute in a body of water. It was used by crewed American space capsules prior to the Space Shuttle program, by SpaceX Dragon and Dragon 2 capsules and by NASA's Orion Multipurpose Crew ...
''
** ''
Wave Race
''Wave Race'' is a 1992 personal watercraft racing video game developed by Pax Softnica and published by Nintendo for the Nintendo Game Boy. It is the first game in the ''Wave Race'' series. The player controls a jet skier around a track aimin ...
''
*** ''
Wave Race 64
is a 1996 racing video game developed and published by Nintendo for the Nintendo 64. Gameplay involves the player racing on a personal watercraft on a variety of courses while successfully manoeuvring the vehicle around various buoys. A multip ...
''
*** ''
Wave Race: Blue Storm''
*
Wetbike
*
Yamaha Superjet
The SuperJet is a stand-up type personal watercraft (PWC) made by Yamaha Motor Corporation. Part of Yamaha's WaveRunner line of watercraft, it was introduced in 1990 and has become one of the most successful stand-up personal watercraft ever made ...
*
Yamaha Wave Blaster
The WaveBlaster is a personal water craft (PWC) made by Yamaha Motor Corporation. Part of their WaveRunner line of watercraft, the Yamaha WaveBlaster 700 (Marine Jet 700TZ) made its debut in 1993. Although technically a runabout style PWC the bl ...
*
Belassi Hypercraft
References
External links
International Jet Sports Boating Association*
{{DEFAULTSORT:Personal Water Craft
Water sports equipment
English inventions