HMS Dumbarton Castle (P265) was an offshore patrol vessel of the British Royal Navy. Her main role was the protection of the offshore assets of the United Kingdom, including oil and gas installations and fisheries out to the limit. She spent much of her time deployed in the South Atlantic as guard ship, patrolling around the Falkland Islands and South Georgia, alternating with her sister ship . Her long association with the Falkland Islands resulted in the ship's company being given permission to add her name to the roll of honour written in white rocks on the hillside opposite Stanley in 2007. Design and construction The was designed for fisheries protection and oilfield patrol duties in the United Kingdom's exclusive economic zone (EEZ). They were a follow-on to the interim which had been ordered in 1975 when the EEZ was extended to 200 miles, and as a result of initial experience with the Islands, was considerably longer in order to improve seakeeping in heavy seas, with the extra length giving greater speed from the same power as the Islands and allowing a large helicopter deck to be fitted. Dumbarton Castle was long overall and between perpendiculars, with a beam of and a draught of . Displacement was standard and full load. The ship was powered by two Ruston 12RK 320 DM diesel engines rated at (with a maximum sustained power of , driving two shafts fitted with controllable pitch propellers. This gave a speed of . The ship had a range of at . The ship was initially armed with a single Bofors 40 mm L/60 gun, although by 1990 this had been replaced by an Oerlikon 30 mm gun on a DS30B mount. The main armament was supplemented by two 7.62 mm machine guns. A large helicopter deck was fitted aft, suitable for landing a Sea King or Chinook helicopter, but no hangar was provided, as the cost of a permanently embarked helicopter would be more than the cost of the ship. She was fitted with Type 1006 navigation radar, which was supplemented with a Type 994 air/surface search radar in 1986, together with a UAN(1) electronic intercept system (based on the Orange Crop system fitted to the Royal Navy's helicopters. The ship had a crew of 6 officers and 39 other ranks, with room for a 25-man detachment of Royal Marines to be carried. Dumbarton Castle was laid