46 C.F.R. § 45.141 Manholes and flush scuttles.
Title 46 - Shipping
Manholes and flush scuttles in position 1 or 2 or within any superstructure other than an enclosed superstructure must have permanently attached covers, unless the cover is secured by closely spaced bolts around its entire perimeter.
Title 46: Shipping
PART 45—GREAT LAKES LOAD LINES
Subpart D—Conditions of Assignment
§ 45.141 Manholes and flush scuttles.
