Certificate of Competency (COC)
"A formal license issued by a flag state administration authorising a seafarer to serve in a specific capacity on board a commercial vessel."
Definition
A Certificate of Competency (COC) is the primary qualification for a maritime officer (Master, Chief Mate, OOW Deck, Chief Engineer, Second Engineer, OOW Engine). It proves that the holder has successfully completed the required education, training, and sea service assessment to perform the duties of their rank.
Issuance
COCs are issued by the maritime administration of a country (the Flag State) in accordance with the STCW Convention. For example, in the UK, it is issued by the MCA; in the US, by the USCG; and in Indonesia, by the Ministry of Transportation (Dephub).
Validity
A COC is typically valid for 5 years. To revalidate it, the officer must prove continued professional competence, usually by showing at least 12 months of sea service in the preceding 5 years or passing a revalidation course.