left Lorient for what would be her last patrol and the last command of Oberleutnant zur See Gerhard Seehausen (posthumously promoted to Kapitänleutnant). A month and ten days after departure, U-66 sighted Silvermaple, a 5,313 GRT British motor merchant in the convoy ST-12. She was sunk after one torpedo hit. Four days later, the boat came upon the French 5,202 GRT St. Louis, which she sank with two torpedoes off Accra, Ghana. The ship broke into three parts, which sank in less than 50 seconds. Four days after the sinking of St. Louis, on 5 March 1944 'U-66 sank the 4,964 GRT British John Holt with two torpedoes, and took the captain, Master Cecil Gordon Hime, and a passenger, Mr Elliott - an agent of the Holt Shipping Company, prisoner. These men were later lost with the U-boat. Nearly three weeks after the sinking of John Holt, the U-boat came across the 4,257 GRT British Matadian, which she torpedoed and sank. After the attack, U-66 was forced to bottom out in the mud as British patrol craft engaged her. U-66 was supposed to be resupplied by , but this boat, a Milchkuh supply submarine, was sunk on 26 April. Sinking On 1 May 1944, U-66 came under attack by American ships from an antisubmarine hunter-killer group formed around . Three Fido homing torpedoes were dropped near the boat, and numerous aircraft from Block Island, along with smaller craft, were designated to hunt for her. On the morning of 6 May, the destroyer escort found the submarine. After an exchange of gunfire and torpedoes, Buckley, under the command of Lieutenant Commander Brent Abel, rammed the submarine. With the two vessels stuck fast, a party of Germans, under the command of U-66s first officer, Klaus Herbig, attempted to climb onto the American escort's forecastle to create a diversion while Seehausen and the remainder of the U-boat's crew worked to free the boat. As American sailors saw the boarding party climbing on deck, hand-to-hand fighting broke out in which a number of Germans were killed or wounded before the U-boat was able to make good its escape. Five armed Germans remained on deck of the destroyer but they were quickly overpowered and taken prisoner. Buckleys 3-inch gun was unleashed on the U-boat as the Americans chased after her, but U-66 then turned and rammed Buckley near her engine room, damaging the ship's starboard