Patrol Boat (PB)

A small constabulary or naval craft for coastal patrol, interception, and boarding, generally under 50 meters and lightly armed. In US Navy hull classification the symbol PB denotes a patrol boat; the Cyclone-class (PC) coastal patrol ships are a larger relative. Patrol boats enforce law inside the territorial sea (UNCLOS Article 3) and contiguous zone (Article 33), with offshore patrol vessels covering the wider exclusive economic zone (Article 56). The role prioritizes speed, shallow draft, and low operating cost over endurance.