Glossary

Key terms used in maritime documentation, verification, and OSINT research.

Open Registry: A ship registry that allows vessels of any nationality to register under that flag, in exchange for fees. Vessels registered in open registries fly the flag of the registry state regardless of where the owner is based or where the ship operates. Panama, Liberia, and the Marshall Islands operate the world's largest open registries.
Flag State: The country under whose flag a vessel is registered. The flag state has jurisdiction over the vessel on the high seas and is responsible for issuing and overseeing statutory certificates including the ship's register, safety management certificate, and crew certification.
P&I Club: Protection and Indemnity club. A mutual insurer providing third-party maritime liability cover, including pollution liability, cargo damage, crew injury, and wreck removal. The 12 leading mutual P&I clubs are members of the International Group (IG), collectively covering approximately 90% of the world's ocean-going tonnage.
International Group (IG): The International Group of P&I Clubs. An association of 12 leading mutual P&I clubs that together provide P&I cover for the majority of the world's ocean-going tonnage. Membership of the IG is a strong indicator of legitimacy for a P&I club.
Classification Society: A technical standards organisation that sets and verifies standards for ship design, construction, and ongoing maintenance. Classification societies inspect vessels and issue class certificates confirming that a vessel meets their standards. IACS members are internationally recognised; classification certificates from non-IACS bodies require additional scrutiny.
IACS: International Association of Classification Societies. The body whose full members are recognised by flag states and port state control authorities for issuing statutory safety certificates. Full IACS members include DNV, Bureau Veritas, Lloyd's Register, ClassNK, ABS, Bureau Veritas, RINA, and others.
IMO Number: A permanent 7-digit identifier assigned to individual commercial ships by the International Maritime Organization. The IMO number does not change when a vessel is re-registered under a new flag, renamed, or changes ownership. It is the most reliable identifier for cross-referencing vessel records across registries and databases.
Port State Control (PSC): The inspection of foreign ships in national ports to verify that the condition of the ship and its equipment comply with international regulations, and that the ship is manned and operated in compliance with applicable law. PSC officers check statutory certificates including class certificates, P&I cover evidence, and registration documents.
Blue Card: A certificate issued by a flag state confirming that a vessel holds valid P&I cover meeting the requirements of the Civil Liability Convention (CLC) or Bunkers Convention. The Blue Card is issued on the basis of confirmation from the P&I club, not by the club itself. A fraudulent P&I club cannot issue a genuine Blue Card.
Statutory Certificate: A certificate required by international maritime conventions (SOLAS, MARPOL, MLC, etc.) that a vessel must carry to trade legally. Statutory certificates are issued or recognised by flag states and their delegated organisations. Classification societies are often authorised to issue statutory certificates on behalf of flag states.