On 18 March 1800, "Agamemnon" was damaged when she ran onto the Penmarks Rocks. She came into Falmouth on 25 March 1800. On her way to port she had encountered , which assisted her and accompanied her into port. With the assistance of the crews from two sloops, the guardship , and troops from Pendennis Castle at the pumps, the crew managed to stop the water level in the hold rising any further. "Agamemnon" made for Plymouth for repairs. Movement caused the leak to gain on the men at the pumps once more, and when she was off Penlee Point, "Agamemnon" fired a gun for assistance. When she reached Plymouth she was lashed to a sheer hulk to prevent her sinking.