How high must the doorsill be raised above the inner bottom surface of the cabinet?

• A. Two inches
• B. One inch
• C. Three inches
• D. Four inches

Answer: (A)

Doorsills are raised to act as a dam against water that can splash into compartments in a ship environment. By elevating the opening above the inner bottom surface, you create a barrier that helps keep the cabinet interior drier during rough seas, waves, or sloshing on deck, which protects stored equipment and reduces the chance of corrosion or damage.

Two inches is a practical balance: it’s high enough to prevent most intrusion in typical sea conditions while still allowing easy opening and closing of the door, normal clearance for hinges and weatherstripping, and accessible interior working space. A one-inch rise may not reliably stop water from entering during heavier seas, whereas three or four inches, though more protective, can complicate door operation, reduce usable space, and make installation or retrofitting more cumbersome.

So, two inches provides effective protection without compromising usability, making it the best choice.