The unit of measurement for the capacity of a vessel whereby one register ton equals 100 cubic feet (2.83 cubic meters). 2. The gross (brutto) tonnage comprises all spaces below the main (tonnage) deck and the enclosed spaces above the main (tonnage) deck less exempted spaces. 3. The net tonnage consists of the gross tonnage less exemptions like ballast tanks, engine room, living quarters, etc. Register tonnage is mentioned on the tonnage certificate.
