“Constructed” in respect of a ship means a stage of construction where:
1. the keel is laid; or
2. construction identifiable with the specific ship begins;
3. assembly of the ship has commenced comprising at least 50 tonnes or 1 percent of the estimated mass of all structural material, whichever is less; or
4. the ship undergoes a major conversion.
Source: International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004, Legislation