The management-level Certificate of Competency required by law to serve as Second Engineer on seagoing merchant vessels — issued under STCW Regulation III/2 (unlimited) or III/3.
The Second Engineer Officer (2/E) Certificate of Competency is a management-level qualification issued under the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW). In the United Kingdom it is administered by the Maritime and Coastguard Agency (MCA); in Ireland by the Irish Maritime Administration via the Department of Transport. The certificate is legally required for any engineer officer serving in the role of Second Engineer on a seagoing merchant vessel, and is recognised in ports worldwide as STCW is an IMO Convention ratified by the vast majority of flag states.
The regulatory framework sits under STCW Regulation III/2 for vessels of 3,000 kW propulsion or more (the unlimited certificate), or STCW Regulation III/3 for vessels of 750 kW to 3,000 kW. The competency standards are defined in STCW Code Tables A-III/2 and A-III/3 respectively. In the UK these are implemented via the Merchant Shipping (Standards of Training, Certification and Watchkeeping) Regulations 2015 (SI 2015/782), with detailed requirements published in MCA Merchant Shipping Notice MSN 1857 (M+F).
The 2/E CoC is not a single taught course but a combination of approved education and training, SQA management-level written examinations, an MCA oral examination, and qualifying sea service. The taught element typically runs from five weeks (Fleetwood Nautical Campus) up to one semester at NMCI Cork, preparing candidates for Engineering Knowledge General and Engineering Knowledge Motor (and/or Steam) written papers. The Second Engineer is the senior officer in the engine department reporting directly to the Chief Engineer, with responsibility for daily machinery operations, maintenance supervision, watchkeeping oversight, and acting as Chief Engineer when required.
Holding a Second Engineer Officer CoC opens roles as 2/E on deep-sea cargo ships, tankers, container vessels, ferries, offshore support vessels, and large commercial yachts above the applicable power threshold. It also qualifies holders for shore-based technical superintendent roles, marine surveying pathways, and positions with flag state administrations. The full merchant navy engineering career ladder runs: Rating or Cadet → EOOW (III/1) → Second Engineer (III/2 or III/3) → Chief Engineer (III/2) → Superintendent or shore technical roles.