In 1974, Diomede, took part in Task Group (TG) 317.2 which was a deployment that caused some controversy back in the UK when the TG, on its way to the Far East/Pacific, visited South Africa, which was at that time under apartheid rule, as well as performing military exercises with the South African armed forces.

They did not visit South Africa on their return, and headed to Brazil for an exercise with the Brazilian Navy.

The following year, Diomede joined the Fishery Protection Squadron, and took part in the Third Cod War.

[6] Also in the 1970s, Diomede was one of the seven Leanders used as the fictional HMS Hero for the BBC TV drama series Warship.

In 1988, Diomede was decommissioned from the Royal Navy and subsequently sold to Pakistan where she was renamed PNS Shamsheer.