What you need to perform it
Primary qualification
- Certificate of proficiency as Rating forming part of an engine-room watch — STCW Regulation III/4 (section A-III/4), required on ships of ≥ 750 kW propulsion power with a manned engine watch.
- Spain: Engine-department Rating certificate (Marinero de Máquinas) issued by the DGMM (training programme regulated by Order FOM/2296/2002 — verify the consolidated text).
Basic STCW
- STCW A-VI/1 Basic Safety Training (survival, fire fighting, first aid, personal safety and social responsibilities).
- Security awareness training A-VI/6-1 and a valid seafarer medical certificate (under Spanish flag, the ISM medical examination).
Specific courses
- Ship- and engine-room-specific familiarisation per the ISM Code.
- Bunkering procedures and spill prevention (company training, indicative).
- Confined spaces and permit-to-work (bilges, tanks, crankcases) — required by most companies.
Indicative experience
Regulation III/4: approved seagoing service with onboard training or specific pre-sea training. As a guide: 2–6 months of supervised watchkeeping before working autonomously within the watch. Promotion to Able Seafarer Engine (STCW III/5) requires 12 months of engine-department seagoing service, or 6 months plus approved training (verify with the Administration).
Observations
Classic route: Wiper → Oiler (III/4) → Able Seafarer Engine (III/5) → pumpman/donkeyman or, via the academic route, engine officer. On UMS ships, rounds and alarm response weigh more than a manned watch. A good oiler detects the failure before the sensor does: touch temperature, smell and a change in noise remain first-class instruments. Proper handling of bilges and transfers has direct MARPOL implications.
What this role does
Keeps the plant running continuously through rounds, greasing and parameter monitoring. The oiler is the trusted rating of the engine watch: the first to notice an abnormal temperature, a leak or an unusual noise is usually the oiler, not the alarm. On UMS ships (unattended machinery space) the role shifts towards scheduled rounds, planned-maintenance support and bunkering operations.
Typical watches
- Engine-room rounds and watch support
Key responsibilities
- Lubrication of main and auxiliary machinery.
- Control of oil levels and operational indicators.
- Support in maintenance, cleaning and bunkering operations.
- Carry out watch rounds, logging parameters and immediately reporting anomalies to the officer of the watch.
Operational scope
- Lubrication
- Rounds
- Maintenance assistance
Profile reviewed by HydroAbyss (2026). Cited rules and timeframes are indicative: the final requirement is set by the flag State, the Administration and each company.