(a) Gross register tonnage means the tonnage of a vessel, less certain spaces exempt under §69.169, and is the sum of the following:

(1) Under-deck tonnage (§69.163).

(2) Between-deck tonnage (§69.165)

(3) Superstructure tonnage (§69.167)

(4) Excess hatchway tonnage (§69.115)

(5) Tonnage of framed-in propelling machinery spaces included in calculating gross register tonnage (§69.121(d)(1)).

(b) Net register tonnage means gross register tonnage less deductions under §69.119 and §69.121.

(c) The authorized measurement organization must issue a U.S. Tonnage Certificate as evidence of a vessel's measurement under this subpart, which must also indicate the vessel's measurement under the Convention Measurement System in subpart B of this part, if applicable. There is no requirement to maintain the U.S. Tonnage Certificate on board the vessel.

[CGD 87-015b, 54 FR 37657, Sept. 12, 1989, as amended by USCG-2011-0522, 81 FR 18731, Mar. 31, 2016]