English: The firing of the first test missile from trials ship HMS Girdle Ness (A387) during the development of the Sea-Slug ship-to-air missile. The antennae of some of the radar equipment used to track the missile can be seen above the bridge of the ship.

The missile is the Armstrong-Whittley 'Sea Slug' Mark I missile. It was the Royal Navy's first generation guided missile and was designed to counter Soviet high-altitude, nuclear-armed bombers. It had the official Royal Navy designation as GWS 1 (Guided Weapons System Mark 1)

Original caption: NAVY TESTS GUIDED MISSILE Her Majesty's Ship GIRDLE NESS, commissioned on July 24th, 1956, as a guided weapon trial ship, has since carried out a number of trials. On September 10th, a test missile, from which a sea to air guided missile is being developed, was successfully fired. Other successful firings have followed. In the House of Commons today (24th October) the Parliamentary secretary of the Admiralty, Mr Simon Wingfield Digby, M.P. have the foregoing particulars in answer to a question by Commander J.F.W. Maitland, Conservative, (Horncastle).[1]