RedactedNarrative: The operator stated while he was pulling tubers he heard a knocking sound coming from the engine. He put the vessel in neutral to check for any issues with the engine. He did not notice any damage. He slowly operated the vessel back to his dock and called the Marina. The vessel was towed to the mainland by the owner. The owner states the engine overheated because he believes the propeller was trimmed up and not fully in the water causing significant damage.