Section 179.360 - Watertight integrity(a) A hatch exposed to the weather must be watertight, except that the following hatches may be weathertight:(1) A hatch on a watertight trunk that extends at least 305 millimeters (12 inches) above the weather deck;(2) A hatch in a cabin top; and(3) A hatch on a vessel that operates only on protected waters.(b) A hatch cover must: (1) Have securing devices; and(2) Be attached to the hatch frame or coaming by hinges, captive chains, or other devices of substantial strength to prevent its loss.(c) A hatch cover that provides access to accommodation spaces must be operable from either side.(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) 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) 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) The height of the watertight coaming for a hinged watertight door need only be sufficient to accommodate the door.