HoH-03.jpg [3/4] Author: J. Stormer Source: Heaven, Hell and Shore Power Copyright: 2005 J. Stormer Credit: J. Stormer Caption: When plugging into your boat the black locking ring needs to be screwed down tightly onto the boat fitting. This seals the lip on the cord against the inlet connector. This prevents msture form entering and prevents movement of the connection as the cord is moved. When the cord is removed the inlet cover should seal tightly to protect the inlet from salt spray.