The recent drowning of an expert swimmer and rowing coach in the Potomac River is leading to a new look at boat safety in the region, just days before one of the busiest -- and most dangerous -- boating weekends of the year.

Yesterday, D.C. Mayor Anthony A. Williams (D) signed emergency legislation requiring children under age 13 to wear life vests aboard moving vessels. And D.C. boating safety officials say they are going to more vigorously enforce life vest rules.

Across the region, members of the rowing community also are reexamining safety protocols. John Steve Catilo, a 20-year-old Alexandria rowing coach and University of Virginia senior, was not wearing a life vest Friday when he fell from his launch and drowned near Reagan National Airport. Nor was he required to wear one. But his fellow coaches began wearing them this week at all times on the water, and other rowing coaches along the Potomac are considering doing the same.

"If this individual had been wearing a life jacket, he'd be alive today," said Joe Carro, a safety specialist with the U.S. Coast Guard and former instructor at the agency's maritime law enforcement school in Yorktown, Va.

Catilo's death is a reminder of how dangerous boating can be even for the experienced. Safety officials said they hope it raises awareness about safety procedures leading up to the July 4 weekend, when crowded waters, alcohol and fireworks can be a dangerous mix.

There were 750 boating fatalities in 2002, according to the Coast Guard. Many involved alcohol use.

Safety officials encourage boaters to take a safety course, get their vessels checked, wear a life vest and stay away from booze.

Maryland safety officials announced yesterday a new boating safety crackdown for the Fourth of July. Dubbed Operation Firecracker, it will include tougher enforcement of safety and alcohol regulations, courtesy inspections and life vest instructions, according to the state Department of Natural Resources.

Last year, between July 1 and July 7, there were 23 accidents involving 22 vessels in Maryland, resulting in two deaths and a dozen injuries, according to state safety officials.

Along the Potomac River, a puzzling and ever-changing patchwork of water safety rules and regulations can sow confusion even among the most conscientious of boaters. The District controls the river from the Wilson Bridge upstream to just past the Chain Bridge, while Maryland has jurisdiction upstream and downstream of those boundaries. Virginia controls tributaries, such as the Occoquan, within the commonwealth.

On the D.C. portion of the river, all children under 13 must wear life vests unless they are below deck. In Maryland, the requirement applies only to children under age 7. Virginia does not require children to wear life vests. A recent regulation imposed by the U.S. Coast Guard, however, does affect Virginia -- requiring all children under age 13 to wear a life vest if they are aboard a vessel in navigable waters. That includes the Chesapeake Bay and rivers such as the James. The Coast Guard rule applies to the 11 states, including Virginia, that have no requirements for children to wear life vests.

Most states also have different safety rules for personal watercraft and water-skiing.

"This stuff is confusing," said Jeffrey E. Decker, boating safety education coordinator for the Virginia Department of Game and Inland Fisheries. "I have empathy for the boater."

Unlike Canada, which has one set of national boating rules, the United States has an array. The U.S. Coast Guard sets safety requirements for the waters it patrols. On other waterways, states have the authority to set standards.

"We work hand in hand to try to keep many of the laws similar. However, the laws are written by legislators, and they have the right to add in the particulars they feel are necessary for their constituents," Decker said.

Boating on the Potomac can be especially confusing. Catilo and his students were in District waters when he drowned, even though they were close to National Airport and had rowed less than a mile and a half from the Alexandria Boat House.

Catilo was in a small motor launch accompanying eight student rowers and a coxswain in a rowing shell. The Coast Guard, District, Maryland and Virginia all require that there be a life vest for each person aboard a vessel. And all jurisdictions require that there be a throwable floatation device on board motorized boats longer than 16 feet.

Even among safety officials, there is confusion as to what rules apply to rowing shells. Coast Guard regulations exempt rowing shells, racing canoes and racing kayaks from life vest requirements. Virginia has a similar exemption, but the District does not.

Lt. Alfred Durham of the D.C. Harbor Patrol's special operations division said the law does indeed require that life jackets be stored aboard the slim racing boats but acknowledged that enforcement is a challenge.

"There is no room on the boat, nowhere to place them. That's why," Durham said. Still, he said he will set up meetings with rowing clubs and schools to see whether they can work out a deal. Durham said one compromise would be that each coach's launch would carry enough life vests for all the coach's rowers.

"I'm not a racer, but we're going to be setting up meetings to find out what we can do," Durham said.

Rowers at the Potomac Boat Club said this week that the worst thing that could happen as a result of Catilo's death is some sort of safety crackdown on rowers by landlubbing lawmakers.

"We've got to take care of each other on the river," said Catherine Kemp, 24, of Arlington, as she was washing down her scull after an early-morning training session.

"It would be impossible to train in a safety vest," said Jessica Busch, 23, of Arlington, who is training for national competition. And Busch knows how treacherous the Potomac can be. In December, she was out on the river when her oar caught a "crab," or tricky wave. The next thing she knew, she was in the 40-degree water without a life vest.

"I just went into shock when I hit the cold water," she said. "And Coach scooped me right out."

Her coach, Matt Madigan, 34, of Alexandria, called Catilo's death a fluke but said it has nonetheless made him rethink his practice of not wearing a life vest when coaching and piloting his small motor launch.

He said that when incidents happen such as Busch's dip in the cold Potomac, coaches need to act quickly. Coaches at the Boathouse in Old Town Alexandria are already wearing vests. Coaches at the Potomac Boat Club and Thompson Boat Center are considering doing the same.

"Accidents do happen," Madigan said.

Jessica Busch of Arlington gets an early workout. "It would be impossible to train in a safety vest," she says.Mike Porterfield, a volunteer coach, hoists a bag of life vests and emergency gear from his launch after working with a crew of rowers.