Oiler

An oiler is an engine department rating whose traditional duties centre on lubricating machinery, maintaining oil records, and standing engine room watches. In modern integrated propulsion plant, the oiler's role has largely merged with that of the motorman, and the terms are used interchangeably in many fleets and flag state regulations. The oiler monitors running machinery, replenishes lubricating oil in sumps and reservoirs, checks for leaks, and carries out routine cleaning of engine room bilges under MARPOL Annex I requirements. Accurate completion of the Oil Record Book Part I — recording all transfers of oily water, bilge water, and oily residues (sludge) — is a critical MARPOL compliance task in which oilers are frequently involved, though the entries must be signed by the officer in charge. Port state control inspectors scrutinise oil record books closely, and discrepancies between logged quantities and physical measurements of tanks can lead to detention and referral to flag state authorities for investigation. STCW III/4 establishes the minimum competency standards for ratings forming part of an engineering watch, including oilers, covering firefighting, watchkeeping duties, and safe work practices.