Most boats come with two types of doors — the weathertight doors are located above the structure of the main deck where they provide security and keep out the weather, whereas the watertight doors are most often found below deck so that they can keep water from flooding into cargo holds, engine rooms, and other areas where water can pose a major hazard. Your watertight doors require proper maintenance in order to operate properly.
Inspect the Sealing Gaskets
All watertight doors have a gasket around their perimeter that helps ensure a tight seal that keeps the water out. If this gasket becomes damaged, then water can leak freely through the door. Inspect the gasket regularly, at least once a month, for any signs of damage. Rough spots, visible stretching or looseness, or other damage can typically be found visually. You may also be able to feel a damaged portion when you run your finger along the gasket. You can also test the gasket for a tight seal by placing chalk powder on the seal. Close the door, then reopen it. If the door sealed properly, then the chalk powder will be completely covering the frame with no gaps. You can wipe off the powder when you are done.
Check the Hydraulic System
Watertight doors typically have a hydraulic system consisting of a wheel to control the seal when you close the door. You need to make sure the system works smoothly and shows no signs of seizing or other damages. If the wheel is difficult to move or if the door seems to stick when you attempt to push it closed or open it back up, the hydraulic system may need to be inspected for damages so repairs can be made to ensure smooth operation.
Test Electrical Systems
Although most watertight doors allow for manual operation, some also operate automatically. These types of doors are common on commercial vessels since they are designed to close if flooding of the lower decks is detected. The door manufacturer can often provide testing protocols for the electrical system, which may require a full inspection of all wiring and a sensor test. There is also typically a test mode you can run, which will automatically shut the doors so you can make sure that the doors are shutting properly when the automatic system is activated.
Contact a marine service that supplies or services watertight doors to learn more.