Port State ControlPSC
Inspection of foreign ships in national ports to verify they meet international safety and environmental standards.
Port State Control (PSC) is the inspection regime by which a coastal state checks visiting foreign-flag ships for compliance with international conventions. Inspectors can issue deficiencies and, in serious cases, detain a ship until faults are rectified.
PSC is the safety net that catches sub-standard ships the flag state may have missed. Inspections are coordinated regionally through Memoranda of Understanding, and a vessel’s detention history is a core input to risk and quality scoring.
On The Maritime
Also known as: PSC, port state control, detention.
Related terms
Memorandum of UnderstandingMOU
A regional agreement coordinating port-state-control inspections — e.g. the Paris and Tokyo MOUs.
Flag State
The country in which a ship is registered, whose laws she sails under and which is responsible for her regulatory oversight.
Classification Society
An organisation that sets technical standards for ship construction and surveys vessels against them throughout their life.
Off-Hire
A period during a time charter when the charterer stops paying hire because the ship cannot perform — e.g. breakdown, drydock or detention.
Plain-English reference definition — our own explanation of a standard shipping concept, not a licensed source or legal advice. See the full glossary or the broader maritime dictionary.
Last reviewed: June 2026.