Under the command of Captain Thomas Kempthorne, Royal Oak took part in the Battle of Cape Passaro on 11 August 1718 as part of Admiral Sir George Byng's fleet.
On 8 March 1737 she was ordered to be taken to pieces at Plymouth, and rebuilt by Peirson Lock as a 70-gun ship according to the 1733 proposals of the 1719 Establishment. She was relaunched on 29 August 1741.[4] Captain Philip Vincent took command and the ship was assigned to the Mediterranean with Rear Admiral Richard Lestock's squadron. Vincent was succeeded by Captain Edmund Willams, Captain Charles Long and finally Captain James Hodsall.[6]
Royal Oak was converted to serve as a prison ship at Plymouth in 1756.[6] The ship was the scene of an incident in January 1759 in which a French prisoner, Jean Manaux, told the warden that his fellow prisoners were forging passes. His fellow prisoners discovered this and, on 25 January, dragged him to a remote part of the ship, gave him approximately 60 strokes with a large iron thimble tied to a rope, then beat him to death after he struggled from his bonds. They dismembered his body in an attempt to dispose of it. At an inquest ashore the next day, one of the prisoners provided information on the murder, which resulted in the hanging of Charles Darras, Louis Bourdec, Fleurant Termineu, Pierre Pitroll and Pierre Lagnal on April 25 at Exeter.[6]