Be sure you know the location of all watertight and weathertight closures, and how to use them. Both watertight and weathertight closures should be inspected regularly. Report any defects to the master or operator immediately.
Keep all watertight closures closed unless actually in use, especially before oncoming heavy weather.
Always keep portlights and deadlights closed and secured when at sea.
Do not paint gaskets. Maintain all gaskets in good condition.
Do not allow cargo or deck gear to block weathertight closures, or any other doorway.
Inspect and grease all dogs regularly.