Overall deadweight tonnage approximately 80 metric tons. Panama also dominates bulk carrier registration in terms of deadweight tonnage. It possessed the greatest deadweight tonnage ever recorded. They have a gross tonnage of around 137,000 tonnes. Container ships accounted for 22.6% of the total gross tonnage of ships scrapped that year. The regulations apply to all marine vessels 400 gross tonnage or above. This would give burthen of 500 tons and a displacement tonnage of about 800 tons. The tax is based on vessels' net tonnage (tons). Gross tonnage is different from gross register tonnage. Vessels under 300 gross tonnage (GT) are not subject to GMDSS requirements. All remaining forms of taxation were legalised and regulated by the Tonnage and Poundage Act. She also holds the distinction of sinking the highest warship tonnage of any U.S. submarine. As completed her gross register tonnage had increased to more than 13,500. With a annual cargo tonnage of 1.74 million, it is the 4th busiest in Europe. The ton in this instance is the burthen tonnage (bm).