On a vessel 36 feet (11.8 meters) or more in length, a visual and audible alarm must be provided at the operating station to indicate high water level in each of the following normally unmanned spaces:
(a) A space with a through-hull fitting below the deepest load waterline, such as the lazarette;
(b) A machinery space bilge, bilge well, shaft alley bilge, or other space subject to flooding from sea water piping within the space; and
(c) A space with a non-watertight closure, such as a space with a non-watertight hatch on the main deck.
source: CGD 88-079, 56 FR 40393, Aug. 14, 1991, unless otherwise noted.
cite as: 46 CFR 28.250