Evolution of PWC and PWC Technology
Today’s PWC can accommodate three people, and feature state-of-the-art, environmentally-friendly engine technology.
The personal watercraft (PWC) concept originated in the 1960s, combining the elements of self-power, small size and a maneuverable, active vessel.
Bombardier Recreational Products, known for its Ski-Doo® snowmobiles, introduced a personal watercraft slightly resembling what we know today as a PWC in the late 1960s, with limited success. This craft is credited for being the first sit-down style PWC. In the early 1970s, Kawasaki Motors Corp. U.S.A. introduced the JET SKI® watercraft, the first commercially successful standup PWC.
There are currently four major companies currently active in the personal watercraft market. In the mid-1980s, Kawasaki's JET SKI watercraft was joined by Yamaha Motor Corp. U.S.A. Their product line of the WaveRunner® model created a market shift from the stand-up to the sit-down style PWC with one- and two-person capacity. Shortly thereafter, Bombardier Recreational Products re-joined the market with their Sea-Doo® line. Most recently, in 2002, American Honda began selling its version of a PWC, the AquaTrax®.
Along the way, two-person sit-down craft quickly took over from the single person stand-up model. Today, three-person family models are the most popular. Multi-person family craft currently make up approximately 99 percent of personal watercraft sales.
PWC popularity grew very rapidly in the early 1990s and what was once a small portion of the recreational boating market became the fastest growing sport in this category. Simultaneously, the PWC industry was for a time the fastest growing segment of the marine business.
Personal watercraft today are 75 percent quieter and up to 90 percent cleaner than pre-1998 models.
Personal watercraft manufacturers are constantly investing in research and development, leading to new technology that improves their product lines. Since 1998, PWC have evolved substantially to meet consumer demands. Today’s PWC are larger, seat up to three people, offer storage space, and are capable of towing a water skier. They are also equipped with new, environmentally-friendly engine technology.
Since personal watercraft were invented, these vessels have been equipped with the same two-stroke engine technology that powers marine outboard motors. It was only in the past decade that marine engine designs changed dramatically. Today, many PWC are fuel-injected and the vast majority of units sold feature state-of-the-art four-stroke engines.
Cleaner and Quieter
PWC manufacturers are meeting and exceeding Environmental Protection Agency (EPA) standards for emissions requirements. Furthermore, all PWC product lines have always complied with all applicable federal and state sound and emissions requirements.
In California, manufacturers are required to go above and beyond EPA standards and also comply with the emissions standards of the California Air Resources Board (CARB). Technological enhancements made to PWC engines have resulted in one of the most environmentally-friendly motorized vessels on the water.
Most of today’s personal watercraft utilize four-stroke, direct-injection and catalyst two-stroke technology allowing up to 90 percent fewer emissions than models manufactured in 1998. Traditional, obsolete technology two-stroke engines in PWC have evolved into high technology catalyzed, direct-injection and four-stoke engines. The older carbureted two-strokes are less efficient because it flushes out or scavenges its cylinders and refills with a mixture of air and fuel after each combustion. This process leads to higher emissions and less fuel efficiency. Because of these inefficiencies, new direct-injection two-stroke designs were developed that scavenge the cylinders with pure air containing no fuel at all. The fuel is then directly injected into the cylinder after the exhaust port is closed.
Beginning with the 2003 model year, all PWC manufacturers produced models with four-stroke engines, universally recognized as the cleanest and most fuel-efficient engines on the water. Today, these four-stroke engines account for the majority of sales and are ever gaining in popularity.
In addition, hull insulation, exhaust system sophistication, materials selection, and other muffling technologies have resulted in personal watercraft that are 70 percent quieter than models produced in the late 1990s.
No Exposed Propeller
PWC engines drive a jet pump that draws water from the bottom of the craft into an impeller, which pressurizes the water and forces it out a nozzle at the rear of the craft. There is no exposed propeller. This “jet” of pressurized water propels and steers the craft when the throttle is engaged.
All boats, including PWC, require power to steer. Each PWC manufacturer tells users to apply throttle to steer. In addition, all new sit-down PWC are equipped with technology that assists the operator in turning the vessel by continuing to supply thrust or activating small fins while the watercraft is decelerating. However, an operator can turn more sharply if the throttle is applied while turning the handlebars.
The development and incorporation of new-technology engines and the sophisticated engine management systems that accompany today’s PWC have allowed for new features to be added to personal watercraft. One such system limits engine speed, thus reducing the maximum speed of the vessel. All PWIA member companies produce vessels with this feature.
In addition to engine and design enhancements, many PWC models today include added comfort and convenience features that were not offered previously on personal watercraft. Such features now include tow hooks, boarding steps, GPS units, side mirrors, increased storage, reverse throttle, and engine cut-off lanyard cords that attach to the operator’s wrist or life jacket. The engine cut-off lanyards automatically turn off the PWC’s engine in the event the operator falls off.
PWC Engine Technologies and Water Quality
Greener: Cleaner, Quieter
PWC technology has changed dramatically for the better. As a result of remarkable technological advancements, today’s PWC are among the cleanest and quietest vessels on the water. Since 1998, manufacturers have reduced emissions by 75 percent and sound by 70 percent. Most of the models sold are equipped with four-stroke engine technology, universally recognized as one of the most efficient engine types. Additionally, today’s two-stroke engine technology has been revolutionized as well. New two-stroke models feature fuel injection systems that are comparable to the low emissions of four-stroke models.
In fact, since 2002, 15 national parks have completed site-specific environmental assessment studies and the results have been consistently in favor of personal watercraft being reintroduced back into these parks. These studies confirm that today’s PWC present no significant environmental harm.
Water and Air Quality
Through new technology, including, since the 2002 model year, 4-stroke and direct injection (DI) 2-stroke engines, personal watercraft manufacturers offer greatly reduced noise and exhaust emissions as well as outstanding fuel efficiency. Personal watercraft manufacturers responded to the regulations set forth by the EPA in 1996 with 2-stroke technology utilizing direct injection and catalytic converters in every model year since 1999. These engines offer as much as a 90 percent reduction in emissions. Today, all manufacturers of PWC offer 4-stroke engines, making the personal watercraft fleet one of the cleanest and quietest on the water.
Older technology 2-stroke engines flush out, or scavenge, their cylinders and refill them with a mixture of air and water each combustion event. Some of this mixture remains unburned, since no combustion is 100 percent efficient, and is lost during the scavenging leading to higher emissions and less fuel efficiency. However, the direct injection designs used by personal watercraft manufacturers since 1999 scavenge the cylinders with pure air containing no fuel at all. The fuel is then directly injected into the cylinder after the exhaust port is closed. This not only results in significantly reduced hydrocarbon emissions, but also improves fuel economy (see charts).
There are a number of different variations of direct injection technologies, such as the Orbital and Ficht, which inject the fuel directly into the combustion chamber after the exhaust port has closed. The Orbital system atomizes a rich mixture of gas and oxygen in a prechamber in a timed valve air blast into the combustion chamber. The Ficht system uses a tiny hammer-like part to force each injection spray into the combustion chamber. The smaller the fuel droplet formation, the quicker it evaporates for combustion. These direct injection systems use nearly 50 percent less oil for a 75 percent reduction in emissions. Personal watercraft manufacturers are also utilizing automotive-based catalyst systems that reduces exhaust emissions by up to 60 percent along with variable oil injection to greatly reduce smoke and oil consumption. The charts on this page display the significant reductions in emissions between new technology PWC and typical outboard motors.
The 4-stroke engine also offers fuel-efficient operation and reduced exhaust emissions. The direct-injection 2-strokes are a new technology, and any difference in fuel economy results from the fact that 4-strokes have been in production for decades with the automobile industry. Both technologies will be addressed in the future to meet consumers’ need for weight, portability, acceleration and clean and quiet operation.