46 C.F.R. § 171.118 Automatic ventilators and side ports.
Title 46 - Shipping
(a) An automatic ventilator must not be fitted in the side of a vessel below the bulkhead deck unless approved by the Commanding Officer, Marine Safety Center. (b) The design and construction of each gangway, cargo and coaling port, and similar opening in the side of a vessel must be approved by the Commanding Officer, Marine Safety Center. (c) In no case may the lowest point of any gangway, cargo and coaling port, or similar opening be below the deepest subdivision load line. [CGD 79–023, 48 FR 51017, Nov. 4, 1983, as amended by CGD 88–070, 53 FR 34537, Sept. 7, 1988]
Title 46: Shipping
PART 171—SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS
Subpart F—Openings in the Side of a Vessel Below the Bulkhead or Weather Deck
§ 171.118 Automatic ventilators and side ports.

