46 CFR § 173.057
Permitted locations for Class I watertight doors
April 15, 2021
(a) Class I doors are permitted in any location on a sailing school vessel which has a mean length of 125 feet (38.1 meters) or less.
(b) Class I doors fitted in accordance with §170.270 of this subchapter shall additionally be marked in two-inch letters “RECLOSE AFTER USE”, and be provided with a remote position indicator at the main navigating station of the vessel.
[CGD 83-005, 51 FR 924, Jan. 9, 1986]