RFA Diligence was a forward repair ship of the Royal Fleet Auxiliary. Launched in 1981 as a support ship for North Sea oil rigs, she was chartered by the British government to support naval activities during the 1982 Falklands War and was later bought outright as a fleet maintenance vessel. She gave assistance to the damaged USS Tripoli and Princeton in the 1991 Gulf War, and to Sri Lanka after the 2005 tsunami. She typically had deployments of 5-8 years in support of the Trafalgar-class submarine on duty east of Suez, with a secondary role as a mothership for British and US minesweepers in the Persian Gulf. Until 2016 Diligence was set to go out of service in 2020. However in August 2016, the UK Ministry of Defence placed an advert for the sale of RFA Diligence. As of 2016 the option for the delivery of future operational maintenance and repair capability for the RFA remained under consideration. However, the 2021 British defence white paper made no specific mention of the need for this capability. In April 2024 she arrived in Turkey for recycling.

HMS Ambush is an Astute-class nuclear-powered attack submarine of the Royal Navy, the second boat of her class.