HMS Compass Rose in the film.
HMS Coreopsis K32
In Royal Navy service, Coreopsis was employed on convoy escort duty in the Atlantic. On 20 October 1940, she rescued 33 survivors from the British cargo ship MV La Estancia sunk by the German submarine U-47 south of Iceland. On 16 November 1942, she rescued 169 survivors from the British merchant ship SS Clan MacTaggart that was sunk by U-92 off Cadiz. On 5 March 1943, she picked-up survivors from the British merchant ships SS Fidra, SS Ger-y-Bryn and SS Trefusis which had been sunk by U-130 northwest of Lisbon.
Royal Hellenic Navy
Coreopsis was transferred to the Royal Hellenic Navy on 1 November 1943, one of several British escort vessels transferred to Greece after April 1941. Renamed Kriezis (Greek: Κριεζής, after the naval hero Antonios Kriezis) but retaining her K32 pennant number, she served as a convoy escort out of Liverpool and on 13 June 1944, escorted Convoy ECM6 which was part of Operation Neptune, the maritime element of the Normandy Landings. She joined the British Mediterranean Fleet in October 1944.
She remained with the Greek navy after the war and was finally returned to the Royal Navy on 1 June 1952.
She collided with HMS Camperdown during the filming, damaging the destroyer.