The Hecla class were designed as combined hydrographic and oceanographic survey ships, built to merchant ship standards and of similar design to . She was laid down at Yarrow Shipbuilders' Blythswood, Glasgow shipyard on 6 May 1964, was launched on 21 December 1964 and was commissioned on 9 September 1965. She had the pennant number A133.
Hecla was 79.3m (260.2feet) long, with a beam of 15m (49feet) and a draught of 4.7m (15.4feet). Displacement was 1915LT light and 2733LT full load, with a gross tonnage of 2,898. She had diesel-electric propulsion, with three Paxman Ventura 12-cylinder diesel engines rated at 1280bhp powering two electric motors, rated at a total of 2000hp and driving one propeller shaft, giving a speed of 14kn. She had a range of 12000nmi at a speed of and at . The ship had a complement of 127 officers and other ranks. She was fitted with a hangar and helideck aft to allow operation of a single Westland Wasp helicopter, while two surveying launches were carried.
In 1982, Hecla was used as an ambulance ship for the duration of the Falklands War. In this role, she ferried wounded from both sides to the main hospital ship, .