Personal water craft

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Pump-jet PWCs such as this Yamaha Waverunner are popular for their speed and maneuverability.
PWC in action.

A personal water craft (PWC) is a recreational watercraft that the rider sits or stands on, rather than inside of, as in a boat. Models have an inboard engine driving a pump jet that has a screw-shaped impeller to create thrust for propulsion and steering. They are often referred by the brand names WaveRunner, Jet Ski, or Sea-Doo.

Most are designed for two or three people, though four-passenger models exist. Stand-up PWCs were first to see mass production and are popular for single riders. The invention of both major types of PWC is credited to Clayton Jacobson II of Arizona, originally a motocross enthusiast.

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[edit] Recreational uses

Many U.S. states require safety training for personal watercraft operators. Modern PWCs include a lanyard attached to a dead man's switch, to turn off the vessel if the operator falls off, provided the lanyard is attached to the operator.

Lake Havasu, Arizona, is used for PWC riders and racers alike; the site has hosted the IJSBA World Finals for PWC racing each October since 1982.

The world record for the distance traveled on a PWC, set by John Moffatt in 2007, is 11,525 miles.[1]

Surfers use PWCs to get to waves and get up to speed with them; this is known as tow-in surfing. PWCs can also be used for towing water skiers on flat water.

[edit] Non-recreational uses

A PWC moored above water.

PWCs are small, fast, easily handled, fairly easy to use, affordable and their propulsion systems, which do not have external propellers, making them safer for swimmers and wildlife. For these reasons, they are preferred for non-recreational use over small motorboats.

Lifeguards use PWCs equipped with rescue platforms to rescue water users who get into difficulties and carry them back to shore. Rescuers use PWCs to pick up flood survivors.

PWCs are used by biologists studying marine life.

PWCs are used for law enforcement. Due to their speed and excellent maneuverability, police and rangers use them to enforce laws on lakes and rivers.

A PWC combined with a wash-reduction system, carrying waterproof loudspeaker equipment and GPS for instructions and distance measurement, has purportedly[citation needed] been used by assistant coaches for rowing sports on the River Tyne.

PWCs are used by the U.S. Navy as surface targets.[citation needed] Equipped with GPS, electronic compass, radar reflector, and a radio modem, the PWC is fully remotable with a two-way link. Its small shipboard footprint allows it to be stored and deployed from the smallest of vessels, and it has been used for target practice for everything from 5" to small arms.[citation needed]

[edit] Emissions

Some personal watercraft carry as many as four passengers, contain up to 260 horsepower (190 kW) engines, reach speeds of up to 70 miles per hour (110 km/h), carry 25 US gallons (95 l) of fuel, and feature amenities such as sun pads and extra padded cruising seats.

Before 1990, PWC emissions were unregulated in the United States. Many were powered by two-stroke cycle engines, which are smaller and lighter than four-stroke cycle 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 to begin regulating PWC and other off-road internal combustion engines. 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 averaging standards, allowing manufacturers to offset more-polluting engines in their range by selling other engines that exceed the standard. California has adopted more stringent regulations than the federal standard.

Even the largest PWC, the Sea-Doo LRV, can be easily loaded onto a trailer and transported from one body of water to another.

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 converters 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, new PWCs are permitted only if they meet the current regulations.

Environmental groups such as the Surfrider Foundation and the Bluewater Network claim that more rapid progress could be made and the large numbers of older watercraft in use continue to emit substantial pollution.

Against this, industry groups such as the Personal Watercraft Industry Association 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.

[edit] Hazards

PWC warning label indicating risk of body cavity injuries

Apart from the obvious hazards of collisions and mechanical breakdowns common to all vehicles, PWCs feature the unique hazard of orifice injuries.[2][3] Such injuries are the logical result of the unusually close proximity of PWC riders to the output end of the pump jet, as well as the fact that personal watercraft are usually not enclosed. 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 (as is commonly found in wetsuits), the jet will easily penetrate any orifice it reaches. The consequences include permanent disability or death.[4][5] For example, in 2006, the California Court of Appeal (First District) upheld a $3.7 million Napa County jury verdict against Polaris Industries arising out of one such incident (which had devastating effects on the victim's lower abdomen).[6]

PWCs present safety concerns in terms of their ability to steer. Since steering is achieved from aiming the nozzle of the pump jet, there is no rudder involved, which means the craft cannot be steered in an emergency breakdown situation. Steering is significantly reduced when the throttle is not being applied; this leads to dangerous situations because it is against one's instinct in an emergency to accelerate. However, turning is not effective without doing so. After market products are available to help with this problem, including different types of rudder steering systems such as Cobra Jet Steering. In 2001 Sea-Doo added the OPAS (Off-Power Assisted Steering) system, which uses rudders installed on the rear sides of the PWC to assist in steering.

[edit] See also

[edit] Footnotes

  1. ^ "Backgrounder: John Moffatt" (PDF). American Power Boat Association. October 17, 2007. http://www.apbaracing.com/071018_news_moffatt_background.pdf. Retrieved on 2008-02-08. 
  2. ^ Jim Stingl, "Have fun on your watercraft, butt beware," Milwaukee Journal Sentinel, 28 June 2000, 1.
  3. ^ Roy Scott Hickman and Michael M. Sampsel, Boat Accident Reconstruction and Litigation (Tucson: Lawyers & Judges Publishing Company, 2003), 78.
  4. ^ Bernard Descottes, Fouzi Lachachi, Issifou Moumouni, Sylvaine Durand-Fontanier, and Ramy Geballa, "Case Report: Rectal Injury Caused by Personal Watercraft Accident," Diseases of the Colon and Rectum 46, no. 7 (June 2003): 971-972. The 16-year-old patient described in this case report was deceased. The autopsy revealed that the primary cause of death was toxic shock syndrome caused by the rectal tear.
  5. ^ David P. Parsons, Harry A. Kahn, John T. Isler and Richard P. Billingham, "Case Report: Rectal Injury Caused by Personal Watercraft Accident," Diseases of the Colon and Rectum 42, no. 7 (July 1999): 959-960. The patient described in this case report survived.
  6. ^ Ford v. Polaris Industries, Inc., 139 Cal. App. 4th 755 (2006). The plaintiff survived due to the heroic efforts of UC Davis Medical Center personnel (the court noted that she required "massive resuscitation") but was permanently disabled by her injuries; for example, she has no bowel control.

[edit] References

Gasoline Boats and Personal Watercraft. Retrieved on May 4, 2005.

[edit] External links


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