To promote water safety and increase law enforcement on local waterways, the Prince William County Sheriff's Office will begin a boat patrol today, adding a marine element to its arsenal for the first time.

Sheriff Lee Stoffregen unveiled the marine patrol program at a ceremony yesterday morning at the Prince William Marina in Woodbridge, where the office's boat will be based. The Sheriff's Office said patrols will begin today and operate only on weekends.

Judy Burke, a Sheriff's Office spokeswoman, said yesterday that reserve deputies will run the patrols, using a donated 1999 18-foot Boston Whaler equipped with police and safety equipment. Although deputies will have the authority to enforce waterway regulations, Burke said their focus will be on boater safety.

"They sometimes will act on any complaints that boaters have about other boaters, but mainly they will be helping people who are stranded out in the water, people that are in distress," Burke said. "Mainly, they will be there for safety and for a law enforcement presence."

Stoffregen started the effort after deputies approached him about the idea and after several residents expressed interest in additional policing on the water. The deputies' aim is to supplement enforcement by the Virginia Department of Game and Inland Fisheries, which regularly patrols the state's waterways. According to the Sheriff's Office, deputies will assist boaters and aid in search-and-rescue operations as well as offer boating safety courses.

Deputies will focus on the Occoquan River, Occoquan Bay, Belmont Bay, Neabsco Creek, Leesylvania State Park, Cherry Hill and Quantico Creek areas, and their service could be extended to Lake Manassas and Lake Jackson if their assistance is needed.