In ascertaining whether a ship is a "new ship" or an "existing ship"
according to the Convention, the term "a similar stage of construction" in
regulation 1.4.2 of the annex to the Convention means the stage at
which:
.1 construction identifiable with a specific ship begins: and
.2 assembly of that ship has commenced comprising at least 50 tonnes
or 1% of the estimated mass of all structural material, whichever is
less.