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 Jet Ski, WaveRunner 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, USA, originally a motocross enthusiast.
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 Wet Dog Race is a 2000 mile Alaskan PWC race with a million dollar purse scheduled to run in 2011.
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 been used by assistant coaches for rowing sports on the River Tyne.
PWCs are used by the U.S. Navy as surface targets. 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.
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 all recreational marine engines including PWC as well as 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 and subsequently New York have 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 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 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, All outboard motors and PWCs are permitted if they meet the 2006 EPA regulations. A number of pre-2006 model year PWC meet that EPA standard.
Environmental groups such as the Surfrider Foundation and the Bluewater Network claim that more rapid progress could be made and the dimishing numbers of pre-1998 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.
Apart from the obvious hazards of collisions and mechanical breakdowns common to all vehicles, PWCs feature the unique hazard of orifice injuries. 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. 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).
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. Kawasaki, Yamaha and Honda include as standard equipment similar "Off Throttle" steering systems.
Gasoline Boats and Personal Watercraft. Retrieved on May 4, 2005.