The Harbor Patrol/Marine Operations Bureau provides around-the-clock law enforcement, marine fire fighting and search/rescue services along the 48 miles of Orange County coastline and within the county's three major harbors at Newport Beach, Sunset-Huntington and Dana Point.

Lieutenant Mark Long is the Harbormaster, overseeing daily operations. Sergeant Steve McCormick serves as the Assistant Harbormaster. The station commanders for the outlying harbors are Sergeant Fritz Von Rettberg at Sunset/Huntington Harbor and Sergeant John Whitman at Dana Point Harbor.

Deputies in the bureau practice a "service-oriented" approach to their duties, and routinely participate in community events and activities in the harbors. Some of these activities include boating education classes for youth and adults, tours, safety inspections, and wildlife rescues.