Category 1 oil tanker – an oil tanker of 20,000 tons deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tons deadweight and above carrying oil other than the above, which does not comply with the requirements for new oil tanker as defined in regulation 1.28.4 of Annex I to MARPOL 73/78 (which does not comply with the requirements for protectively located segregated ballast tanks).
Category 2 oil tanker – an oil tanker of 20,000 tons deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tons deadweight and above carrying oil other than the above, which complies with the requirements for new oil tanker as defined in regulation 1.28.4 of MARPOL 73/78, Annex I (which complies with the protectively located segregated ballast tank requirements).
Category 3 oil tanker – an oil tanker of 5,000 tons deadweight and above but less than that specified in regulation 20.3.1 or 20.3.2 of Annex I to MARPOL 73/78.
