The entry-level MCA Certificate of Competency that qualifies you to stand an unsupervised engineering watch on seagoing merchant vessels of 750 kW or more.
The Engineer Officer of the Watch (EOOW) STCW III/1 is the entry-level officer certificate in the UK merchant navy engineering pathway. It certifies the holder to stand an unsupervised engineering watch on a seagoing vessel — specifically to be the officer in charge of the main propulsion plant and associated auxiliary machinery, whether in a manned engine room or as the designated duty engineer (DDE) in a periodically unmanned (UMS) engine room. Without it, an engineer can only work as an engine-room rating, not as an officer in charge of a watch.
The qualification is governed by the STCW Convention, Regulation III/1, and Section A-III/1 of the STCW Code (Table A-III/1 competency standards). In the UK it is administered and issued by the Maritime and Coastguard Agency (MCA) under Merchant Shipping Notice MSN 1857 (M+F) Amendment 1, with written examinations set and assessed by IAMI (the Institute of Marine Engineering, Science and Technology's examining board). It is mandatory under the Merchant Shipping (Standards of Training, Certification and Watchkeeping) Regulations 2015 for any seafarer serving as an engineering officer on a merchant ship of 750 kW or more.
Written examinations are taken in two or three modules — Engineering Knowledge General, Engineering Knowledge Motor, and/or Engineering Knowledge Steam — depending on the vessel type endorsement required. An MCA oral examination follows. The certificate is issued with a motor and/or steam ship endorsement based on the examinations taken and sea service completed.
Holding the EOOW III/1 CoC opens the door to serving as 4th Engineer or 3rd Engineer on any merchant vessel requiring STCW-certificated engineering officers — from cargo ships and tankers to passenger vessels and offshore support vessels. The typical shipboard rank progression runs: Engine-room Rating → EOOW (4th/3rd Engineer) → Second Engineer → Chief Engineer. The EOOW is the essential first step onto the officer ladder and is globally recognised across all flag state administrations party to the STCW Convention.
The EOOW III/1 Certificate of Competency must be revalidated every five years. Revalidation (via MCA form MSF 4201) requires either continued approved sea service in the relevant grade or completion of an approved refresher course, together with current STCW supporting certificates (Basic Safety, Proficiency in Survival Craft, Advanced Firefighting and others as applicable). Revalidation is processed through the MCA's electronic application system. Additionally, engineer officers may need to demonstrate documentary proof of High Voltage (HV) system training or relevant sea service — at least six months in the preceding five years, or three months in the preceding twelve months — as required by the Manila 2010 Amendments.
Course fees shown are for the academic and examination preparation element only. Candidates must also budget separately for: all four STCW Basic Safety Training certificates if not already held (approximately £600–£1,000); the MNTB Training Record Book and Action Plan (approximately £150–£210); the MCA oral examination fee; and an ENG1 medical certificate (approximately £150–£250).