(a) A hatch exposed to the weather must be watertight, except that the following hatches may be weathertight:

1. (1) A hatch on a watertight trunk that extends at least 305 millimeters (12 inches) above the weather deck;
2. (2) A hatch in a cabin top; and
3. (3) A hatch on a vessel that operates only on protected waters.

(b) A hatch cover must:

1. (1) Have securing devices; and
2. (2) Be attached to the hatch frame or coaming by hinges, captive chains, or other devices of substantial strength to prevent its loss.

(d) A weathertight door must be provided for each opening located in a deck house or companionway. Permanent watertight coamings must be provided as follows:

1. (1) On a vessel on an exposed or partially protected route, a watertight coaming with a height of at least 150 millimeters (6 inches) must be provided under each weathertight door in a cockpit or a well, or on the main deck of a flush deck vessel.
2. (2) On a vessel on a protected route, a watertight coaming with a height of at least 75 millimeters (3 inches) must be provided under each weathertight door in a cockpit or a well.
3. (3) The height of the watertight coaming for a hinged watertight door, need only be sufficient to accommodate the door.