But even as the number of Clean Marinas grows to 130, that represents only 20 percent of all boating facilities in Maryland.

The Maryland Department of Natural Resources maintains, though, that the program is doing its job in getting marinas to be more friendly to the environment.

"This moves the ball forward," said Donna Morrow, who runs the Clean Marina Initiative.

She said participating marina operators are excited to volunteer for the program, and often quickly make changes to lessen their impact on the environment.

If, instead, regulations were tightened on marinas - and they were legally forced to make changes - that could be "off-putting and negative," Ms. Morrow said.

The voluntary program was developed in the 1990s as the result of a federal law that required states to reduce pollution from various sources, including marinas and recreational boating.

Maryland proposed developing a voluntary program with the help of the marine industry. The federal government approved the plan and the Clean Marina Initiative has been growing ever since.

Bob DeYoung, who works with marinas seeking Clean Marina designation, said the voluntary approach is positive.

"It's a proactive stance rather than a reactive stance," he said.

The goal of the Clean Marina program is to have 25 percent of all marinas certified. Ms. Morrow anticipates the program will continue after reaching that milestone.

"I don't think there's any reason - even if we got 25 percent tomorrow - to fold up our tent," she said.

Rod Jabin, president of the Marine Trades Association of Maryland, said marinas embrace the program.

"We all have a stake in this Clean Marina program ... Without the assets of the Chesapeake Bay and other bodies of water, we're struggling," said Mr. Jabin, who is with Bert Jabin's Yacht Yard, a Clean Marina in Annapolis. "We are trying to do the best job we can to be stewards of the

Chesapeake Bay."

Participating marinas can choose from a variety of pollution-prevention practices to gain certification, similar to how green buildings are rated. The flexibility allows marinas of all shapes and sizes to participate.

The latest local marinas to earn Clean Marina certification are Anchor Yacht Basin in Edgewater, Atlantic Marina in Pasadena, Chesapeake Yacht Club in Shady Side, Clark's Landing of Shady Side and Clark's Landing of West River. Five marinas from elsewhere in the state also earned certification.

The Clark's Landing location in West River played host to an awards ceremony yesterday. The marina is unusually quiet compared with most marinas, as it's primarily a floating showroom for the company's expensive yachts.

Employees have been trained in how to handle spills of fuel, oil or other harmful substances, said Nancy Pack, operations manager. There's a pumpout station to remove waste from boats, and used oil is burned to heat the buildings. Customers who buy yachts are given pamphlets about clean boating, too.

"We're very proactive," Ms. Pack said.

A list of Clean Marinas is posted at www.dnr.state.md.us/boating/cleanmarina.