The highest-level engineering licence in the merchant navy — certifying you to command the engine department on any seagoing vessel.
The Chief Engineer Officer Certificate of Competency (CoC) is the pinnacle engineering qualification for merchant seafarers. In the UK it is issued by the Maritime and Coastguard Agency (MCA); in Ireland by the Department of Transport. The qualification is governed by the International Convention on Standards of Training, Certification and Watchkeeping (STCW), specifically Regulation III/2 and Section A-III/2 of the STCW Code, as established by the International Maritime Organisation (IMO). The UK's domestic implementation is set out in Merchant Shipping Notice MSN 1857 (M+F). In UK Merchant Navy tradition this is often referred to informally as a "Class 1 Engineer" certificate.
There is no single mandatory classroom programme — the CoC is achieved through a combination of SQA (Scottish Qualifications Authority) Management Level written examinations and an MCA oral examination. Most candidates attend a preparation programme at an approved maritime college to study for the written papers, then sit a separate MCA oral with an authorised examiner. Written examination modules typically cover Engineering Knowledge General (thermodynamics, applied mechanics, naval architecture), Engineering Knowledge Motor (diesel propulsion, auxiliary machinery), Applied Heat, and Electrotechnology, with a Steam endorsement option available. Both written and oral examinations must be passed within three years of each other for the CoC to be issued.
Any officer intending to serve as Chief Engineer Officer on a merchant vessel with main propulsion machinery of 3,000 kW or more is legally required to hold a CoC at STCW III/2 level. Second Engineer Officers on large vessels are also required to hold — or be working towards — STCW III/2, as STCW mandates that the Second Engineer must be capable of assuming the Chief Engineer's duties at any time. Operating without the required CoC is a criminal offence for both the seafarer and the ship operator.
Holding an unlimited Chief Engineer Officer CoC positions you at the top of the seafaring engineering career ladder, with no power restriction on the vessels you may serve aboard. Ashore, the certificate is widely recognised by ship management companies, flag state administrations, and classification societies as evidence of the highest professional engineering competence. Many Chief Engineers move into technical superintendent roles overseeing fleets; others progress to marine surveying, flag state work, or MSc study to formalise their expertise for shore-based management careers.
The NMCI Cork seven-week programme leads to the Irish Department of Transport CoC (aligned with STCW III/2 and III/3), with SQA written examinations sat immediately following the taught phase. UK providers offering written examination preparation and dedicated Chief Engineer orals preparation courses include Warsash Maritime (Southampton Solent University) and Glasgow Maritime Academy — contact providers directly for current intake dates, fees, and availability.