OPINION Water Hazards Personal watercraft are more than noisy; they're polluters.   The past week found many Portlanders trying to beat the heat. Frappuccinos, baggy clothes and super-short haircuts are OK, but one of the purest escapes is a trip to the Willamette, where the cool zephyrs alongside the river can pull the temperature down a good 10 degrees. An additional benefit of Portland's waterway is the sensory feast it provides. Along the riverbanks of Willamette Park, for example, one's eyes are treated to the slow ballet of sailboats tacking across the river, one's nose is piqued by the scent of burgers barbecuing and one's ears--well, one's ears are battered by the 75-decibel whine of Jet Skis. We must concede we felt a certain glee when the Washington State Supreme Court last month upheld the right of San Juan County to ban personal watercraft. We, too, find ourselves aggravated by these river motorcycles--a breed of boat that is too fast, too loud and too popular. Ten years ago, there were 800 personal watercraft registered in Oregon; today there are more than 13,000. While San Juan County put the brakes on these craft largely for aesthetic reasons, a nonprofit group in California says there is a more fundamental problem with personal watercraft: They are environmental hazards. For the sake of the polluted Willamette, the findings should prompt this state to tighten up or even ban the use of personal watercraft. The culprit, says the Bluewater Network, is the two-stroke engine, the notoriously inefficient motor used on personal watercraft and other outboard engines. Two-stroke engines are famously dirty; they discharge 20 to 30 percent of their fuel--a mixture of oil and gas--into the water. According to the Bluewater Network, two-stroke motors produce the equivalent of 37 Exxon Valdez spills every year, the bulk of which, the group claims, comes from high-horsepower personal watercraft, the fastest-growing segment of the boating industry. The state agency in charge is the Oregon State Marine Board, an $18 million-per-biennium organization that has managed to ban personal watercraft from a number of rivers and set clear speed limits for them. Some think that further restrictions would encourage manufacturers to build more efficient engines. Because the federal government seems slow to react, it's up to local communities to take back their waterways. That's what a California assemblywoman did early this year when she introduced a bill that called two-stroke marine engines "among California's largest sources of toxic water pollution." The bill, which would have prohibited the sale of high-emission two-stroke engines after 2002, ultimately failed. Residents have taken action in San Juan County. Key West, Fla., has severely restricted personal-watercraft use. And many national parks are considering banning personal watercraft. Banning or further restricting jet skis on the Willamette wouldn't by itself remedy the river's embarrassing pollution level. But it would certainly help. It would also give the industry one more incentive to do what it eventually must--produce a cleaner boat engine. Oregon has demonstrated this type of leadership in the past. Why, during the dog days of August, can't it do so again?   originally published August 5, 1998