The Type 12 frigate Rhyl (1959) in dry dock No. 8 in Devonport Dockyard, Plymouth, Devonshire. The ship was in the dry dock from 5 August to 7 September 1971. The photographer is standing on the floor of the dock looking to starboard showing the Hull Outfit 20, sonar type 177, dome between 15 and 19 stations in the keel. The dome is partially raised and divers' search lines have been painted on the hull. A name and description board is on the floor of the dock and a scale stick is propped against the hull.