ITC69

The International Convention on Tonnage Measurement of Ships, 1969 (ITC69) entered force 18 July 1982 and set the single global standard for gross tonnage (GT) and net tonnage (NT). GT = K1 times V, where V is total enclosed volume in m3 and K1 = 0.2 + 0.02 log10(V); NT is derived from cargo-space volume, draft, and passenger numbers. Both are dimensionless index numbers, not weights or volumes, and they replaced the older Moorsom and Suez/Panama national systems for international certificates.