RedactedNarrative: On 9/06/2021 at approximately 1118, we were on Dale Hollow lake, still in the "no wake" zone of Mitchell Creek Marina. We were approached by Owner, who was on a jet ski. He advised that he needed a boat accident report. He advised that his houseboat was struck by the houseboat in the slip next to his, while the operator was trying to dock his houseboat. We followed Owner over to his houseboat that was docked the D dock. The neighbor''s houseboat was already in their slip on D Dock. Owner advised that the houseboat, which is vessel 1, struck his houseboat, which is vessel 2. Vessel 2 was docked, its assigned slip on Dock D. Owner advised that V1 struck the rear area of V2 causing damage to the slide on pylon of V2, which was located on the port side of the stern. I made contact with the operator of V2, OP1. He advised that he was trying to dock V1 and his engine lost power. OP1 advised with the engine off and the wind conditions, he could not avoid striking V2. He advised that he struck V2 with the starboard side of the bow of V1.