Launched in 1942 for the Ministry of War Transport, the Hoedic class steel steam tug Empire Ace was launched from the Selby yard of Cochrane and Son Ltd (Yard no 1255) on 12th September 1942. She measured 118.0′ x 28.5′ x 12.4′ and her tonnage was 275 gross tons. She was powered by a triple expansion steam engine by D C Holmes and Co Ltd., Hull delivering 825 ihp.
Built for the Royal Navy she served for three years during the Second World War operating as a Fleet tug off the west coast of Africa and in the Mediterranean. In March 1944 she was hit by a bomb in an air raid off Naples but she was successfully raised and repaired to re-enter service based in Malta. After the war she continued her service based in Malta. In 1947 she was renamed Diligent and continued service there until 1958 when she was transferred to Devonport and returned to her original name. Refitted at Rosyth in 1960 she was transferred to the Clyde where she was loaned to the US for a period supporting the nuclear submarine operations at Holy Loch. Returning to Royal Navy support duties as a Fleet Auxiliary she continued to operate in the Clyde estuary area until she met her fate near Campbeltown.
She ran aground at Glenhervie, Kintyre on the 11th November, 1968 in high winds and rough seas. The Campbeltown lifeboat was called out but by the time they reached the scene the twelve man crew of the tug had made it safely to the shore in the ship’s boat and liferaft. The position of the tug made successful salvage unlikely but the boom defence ship Mandarin stood by for a number of days hoping to take her off and pumps were put on board to keep her free of water. This continued for almost a month when, with weather closed in for the winter, they were forced to give up. They left the tug to its fate and the mercies of the winter gales. The ship was pounded by storms during the following months but eventually, in June 1969, she was successfully refloated. However, by this time she was too badly damaged to be economically repaired and she was towed to Campbeltown where she was broken up for scrap at the yard of Archibald Macfayden.
The position shown on the map is approximated as precise location of stranding not recorded.