Gently down the stream? Pleasure boating faces new regulations and stiffer penalties in efforts to curb water pollution.

Mother Ocean, how do we pollute thee? Let us count the ways: There's garbage dumped and fuel that spills and toxic boatbottom paints; bathroom waste, beer cans dumped in haste and tampons on the beach... Indeed, while sailing from California to Hawaii last summer, adventure boater Bill Forrest didn't need his compass--he just followed the highway of plastic bags tossed overboard by other boaters.

The U.S. Coast Guard (USCG) has recently widened patrols to nab seagoing litterbugs. Boaters are routinely checked for violations by the USCG which checks to ensure that they have aboard a "reasonable amount of garbage." In the realm of other forms of waste, the federal Water Pollution Control Act of 1972 requires all boats to be equipped with Coast Guardapproved holding tanks or treatment systems. This law also prohibits discharge of even treated waste in many areas. But, despite the vigilance of USCG "potty patrols," raw sewage still flows into our waters.

In southern California, residents of Avalon Island were alarmed by fecal coliform (a bacteria) counts of over 500 parts per milliliter (ppml) in their water (Los Angeles County considers 100 ppml to be safe). So they started placing dye tablets in the toilets of visiting boaters. The tablets release a green dye into the water, showing where toilets have been illegally pumped out. More than 225 fines have been levied against transgressors, according to city manager Chuck Prince. "Today, Avalon has a [fecal coliform] count of only 10 to 20 ppml; sometimes the count is too small to be measured. We have the cleanest harbor in California."

Encouraged by this, California state senator Tom Hayden introduced a bill that would authorize marinas statewide to initiate dye tablet programs. Opponents of the measure fear yet more government restriction and damage to their plumbing systems and the ocean from the dyes, which contain disodium fluorscein. Although Dean Potter of the manufacturing company, Formulabs, refrains from saying this chemical is nontoxic, he says "it is biodegradable and is currently used by the Navy in sea markers"--rescue devices used to spot downed pilots in the water. Many boaters believe they are being unjustly targeted for sewage pollution that emanates less from pleasure craft than from the combined sewage outflow from storm drains during heavy rains.

In fairness to the boaters, one problem they face, according to Elaine Dickenson of the boater advocacy organization, Boat U.S., is that central boat toilet pump-out facilities are "woefully inadequate." Pleasure boater George Neill of Richmond, California sailed to different marinas all over San Francisco Bay looking in vain for a station where he could pump out his full holding tank. "Everything was either broken or unavailable," he recalls. This situation may soon improve: The Clean Vessel Act of 1992 will provide, from taxes on marine fuels, $40 million over the next five years to build and improve pump-out stations.

A less conspicuous but equally troublesome threat to water quality is the paints used on boat bottoms: Tributyltin (TBT), a tin compound used in marine bottom paints, caused alarm in the late 1970s in France, where Pacific oysters were being found with gruesome deformities. Later on, in Britain, researchers discovered female dog whelk snails with penises. Both problems were directly linked to TBT in the sediment near marinas and boat repair facilities.

"Such a graphic correlation is virtually unheard of in environmental science," notes Mike Rexrode of the U.S. Environmental Protection Agency (EPA). "These deformities are caused by very tiny amounts of TBT -- just .02 parts per billion in the case of the Pacific oyster, and .7 parts per trillion in the case of the dog whelk snail." In 1981, France banned the use of TBT paints for all boats under 25 meters long.

After deformities were confirmed in oysters in Coos Bay, Oregon, and TBT poisoning was discovered in Chinook salmon, mud crabs and green algae, the U.S. Congress in 1988 passed the Organotin Antifouling Control Act to prohibit most TBT paints. Copper paint is now the bottom paint of choice--but copper corrodes aluminum, so TBT is still permitted for aluminum-hulled boats.

In France the TBT ban's effects have been dramatic: During the first year, the deformity rate among Pacific oysters dropped to 80 percent; by 1984 only 10 percent of the oysters were exhibiting deformities. The U.S. ban has not yet produced such results. "TBT is still out there," states Rexrode. "Studies in Galveston, Texas, Lake Erie, Narraganset Bay in Rhode Island, and Puget Sound in Washington found TBT concentrations in excess of one part per billion. That's very significant. We're finding contamination in unexpected places, such as in the middle of bays. We don't understand why this is happening." Yet, lack of funding is delaying much-needed follow-up studies.

Officially, anyone discharging anything that "produces a sheen on the water" is subject, under the Oil Pollution Control Act, to a Coast Guard fine of up to $10,000 and a six-month jail term. But, according to Andre Mele, author of the newly-released book Polluting for Pleasure, the most devastating pollution problem is the often unintentional discharge of unburned fuel into the water and air from marine gasoline engines. Mele calculates that the nation's 12 million powerboats spew 400 million gallons of unburned fuel into the water--"the equivalent of five Exxon Valdez accidents"-each year.

The chief culprit, according to Ken Zerafa of the EPA, is the two-stroke smaller outboard engine, accountable for 76 percent of the volatile organic compounds (VOCs) released into the air by marine engines. In a typical two-stroke engine, Zerafa explains, extra fuel that enters the cylinder on the intake stroke is used to expel the exhaust gases. This raw fuel then goes directly into the ocean and atmosphere.

A 1990 EPA study validated concerns about marine engine pollution. Although Zerafa notes that regulations are "years away," the marine industry is already responding with such new technologies as the four-stroke outboard engine, being sold by Honda and Yamaha, and a diesel fuel outboard engine, lacking VOC emissions, by Yanmar. According to Mele, both Ford and Chrysler are developing alternative engines designed to combust more efficiently and reduce hydrocarbon emissions and VOCs by 90 percent. Mele says that reducing the number of cylinders in marine engines, fitting marine diesels with traps and filters, and redesigning hulls and propellers would also help.

In addition, he writes, "Boaters can be educated to enjoy boating at 15 knots instead of 30. Better still, five knots instead of 50."

Contact: The Center for Marine Conservation, 1725 DeSales Street NW, Washington, DC 20036/[phone]; Boat U.S., 880 South Pickett Street, Alexandria, VA 22304/[phone]. Polluting for Pleasure ($22.95 postpaid) is available from: W.W. Norton & Company, 500 Fifth Avenue, New York, NY 10110/[phone]. To report illegal discharges of oil or garbage into the ocean, contact the Coast Guard at: [phone].