(a) Except as provided in paragraph (b) of this section, a tank vessel underway or at anchor must have all closure mechanisms on the following openings properly closed:
- (1) Expansion trunk hatches;
- (2) Ullage openings;
- (3) Sounding ports;
- (4) Tank cleaning openings; and
- (5) Any other tank vessel openings that maintain the seaworthy condition of the tank vessel and prevent the inadvertent release of oil or hazardous material in the event of a tank vessel accident.
- (b) No person may open any of the closure mechanisms in paragraph (a) of this section while the tank vessel is underway or at anchor except when authorized and supervised by a licensed or credentialed officer or the tankerman required by 46 CFR 31.15-5(a).
[CGD 75-124, 45 FR 7175, Jan. 31, 1980, as amended by CGD 86-034, 55 FR 36255, Sept. 4, 1990; USCG-2006-24371, 74 FR 11212, Mar. 16, 2009]