In September 1970, Grey Rover took over from RFA Black Ranger as Flag Officer Sea Training (FOST) tanker.

She carried out replenishment at sea (RAS) trials with STUFT ships en route to the Falkland Islands in the southwest approaches to the English Channel whilst herself was based at Portland.

[4] In January 1994, Grey Rover berthed at Cape Town, South Africa, in company with HMS Norfolk for a five-day visit.

On 2 February 2006, while supporting the Type 42 destroyer HMS Southampton in the Caribbean as part of Atlantic Patrol Task (North), Grey Rover was involved in the boarding of merchant vessel MV Rampage and the seizure of 3.5 tonnes (3.4 long tons; 3.9 short tons) of cocaine with an estimated street value of £350 million.

[6] In November 2004, the Parliamentary Under-Secretary of State for Defence Procurement Lord Bach announced that Grey Rover would have a decommissioning date of 2007.