The only ship attacked on the last war patrol of SMS U-64 was a former German cargo ship. The Moltkefels was built for Deutsche Dampfschiffarts-Gesellschaft (Hansa Line) in 1904 and in 1914 she was taken over by the Admiralty and put under the management of Jos. Chadwick & Son in London and renamed Kandy.

On June 17, 1918 Kandy was part of a convoy in the Mediterranean about 110 miles west of Sicily when
Kapitänleutnant Robert Moraht looked through the periscope of U-64 and sighted the ships. The first torpedo fired missed, and according to Moraht the ship turned to ram him, but he took his U-boat under the ship, came up and was close enough to the next ship in line that he fired a torpedo almost without even making the basic calculations. He was close enough to hit her and he did. Kandy was hit amidships, but the damage was not very severe and she made port. This turned out to be his last shot in the Great War.

Due to a "hazy periscope" Moraht had misjudged his location, believing he was alongside the convoy he tried to run parallel with the ships, but as it turned out he was inside the convoy and did not see the escort bearing down on his boat. When he realized his boat was within the convoy he ordered a dive, but before they reached forty feet a depth charge exploded near the after section of the submarine. The boat went dark and water was coming into the stern, the dive steering gear was knocked out, worse yet they were now rising out of control.

When they broke the surface they came under a fusillade of gunfire, having stopped the leak in the stern, Moraht ordered another dive, on the surface he was little more than a sitting duck. They reached sixty feet before the dive steering gear again failed and the boat once again began to rise. Once on the surface the submarine was quickly rammed by HMS Lychnis and for the third time U-64 went under the waves. With no way to control the boat and stop the descent, Moraht ordered the tanks blown which brought her to the surface for the last time.

The only course of action left to the Germans was to fight it out, and according to Moraht his men manned the gun and fired on the British ships until a shell from HM Trawler Partridge II sent the boat to the bottom. U-64 sank so quickly that only a few men were able to get off the boat, and fewer still were rescued, only five men, including Moraht, were picked up by the British ships. Moraht had nearly drowned awaiting rescue, he later stated that he barely remembered being rescued, after being taken underwater two or three times still wearing his leather uniform and boots he was exhausted and if one of his men had not alerted the British that the Captain was still out there he may not have been rescued at all. Thirty-eight of his men however were lost in the action.