Engine Department
The engine department keeps the ship moving. The Chief Engineer manages it; the Second Engineer runs the watchkeeping programme and maintenance; the watchkeeping engineers stand the engine room watch; the ratings work alongside them.
Engine officers hold Certificates of Competency under STCW Chapter III. Ratings hold Certificates of Proficiency. These are distinct instruments — this page maps both tracks.
The officer ranks
Two STCW competence levels: Management (Chief Engineer, Second Engineer) and Operational (the watchkeeping engineers and the Electro-Technical Officer). The Engineer Cadet is a training berth working toward the first Certificate of Competency.
Management level · STCW Regulation III/2
Chief Engineer Officer
Commands the engine department. Responsible for the operation and maintenance of propulsion machinery, auxiliary machinery, fuel management and compliance with MARPOL engineering requirements. Reports to the Master. The Second Engineer Officer and Electro-Technical Officer report to the Chief Engineer. Does not typically stand a routine engine room watch.
Certificate: Certificate of Competency — Engine, Management Level, capacity "Chief Engineer Officer" (STCW Regulation III/2; Table A-III/2)
Management level · STCW Regulation III/2
Second Engineer Officer
Second in command of the engine department. Directly supervises the watchkeeping engineers and manages the planned maintenance programme. Responsible for oil record book maintenance. On UMS vessels, frequently acts as the designated duty engineer during the unmanned period.
Certificate: Certificate of Competency — Engine, Management Level, capacity "Second Engineer Officer" (STCW Regulation III/2; Table A-III/2)
Operational level · STCW Regulation III/1
Third Engineer Officer
Officer in Charge of an Engineering Watch. Responsible for auxiliary machinery maintenance — air compressors, purifiers and associated systems. Stands the engine room watch in the three-watch or equivalent manned arrangement.
Certificate: Certificate of Competency — Engine, Operational Level (STCW Regulation III/1; Table A-III/1)
Operational level · STCW Regulation III/1
Fourth Engineer Officer
Officer in Charge of an Engineering Watch. Most junior watchkeeping engineer. Typically responsible for deck machinery, pumps and fuel transfer operations in addition to standing the engine room watch.
Certificate: Certificate of Competency — Engine, Operational Level (STCW Regulation III/1; Table A-III/1)
Operational level · STCW Regulation III/6
Electro-Technical Officer
Responsible for electrical systems, automation and control systems, electronic navigation equipment and refrigeration plant electrics. Reports to the Chief Engineer. A distinct officer role with its own Certificate of Competency class, introduced as a mandatory STCW rank by the Manila Amendments 2010.
Certificate: Certificate of Competency — Electro-Technical Officer (STCW Regulation III/6; Table A-III/6)
Training berth · Support level
Engineer Cadet
Trainee engineer accumulating STCW-approved sea service toward the first Certificate of Competency. Works under the supervision of certificated engineers. Required to maintain an approved training record book. Not a watchkeeping officer.
Documentation: Approved training record book and STCW-approved seagoing service (Regulation III/1 requirements)
The engine ratings
Engine ratings hold Certificates of Proficiency — not Certificates of Competency. The Able Seafarer Engine is the qualified watchkeeper; the Motorman is the entry watchkeeping grade; the Wiper is the entry learning role.
Able Seafarer Engine
Qualified engine rating. Assists with engine room watchkeeping, carries out machinery maintenance and performs duty rounds under the UMS regime. The standard working grade between Motorman and a supervisory position.
Certificate: Certificate of Proficiency — Able Seafarer Engine (STCW Regulation III/5; Table A-III/5)
Motorman
Entry engine rating. Stands the engine room watch under supervision, carries out lubrication and basic maintenance. Also referred to as Oiler on older vessels.
Certificate: Certificate of Proficiency — Rating Forming Part of an Engineering Watch (STCW Table A-III/4)
Electro-Technical Rating
Qualified rating in the electrical and automation discipline. Assists the Electro-Technical Officer with electrical maintenance, instrument calibration and control system support. Introduced by the Manila Amendments 2010.
Certificate: Certificate of Proficiency — Electro-Technical Rating (STCW Regulation III/7; Table A-III/7)
Fitter
Skilled trades rating. Carries out machining, mechanical repair, workshop operations and engine overhauls. Qualifications are trade-based — City & Guilds, NVQ or equivalent. No STCW Certificate of Proficiency specific to this role; carried at company discretion.
Certificate: Trade qualification (C&G, NVQ or equivalent); no distinct STCW CoP for this grade
Wiper
Entry-level engine department grade. Carries out basic cleaning, maintenance assistance and learning duties under supervision. No STCW Certificate of Proficiency is assigned to this grade.
Certificate: No STCW CoP specific to this grade
How the engine room watch works.
Manned Engine Room
4 on · 8 off · continuous
Engine room staffed continuously by a watchkeeping engineer. The standard three-watch rotation — 4 hours on, 8 hours off. Required where a UMS class notation is not held and during restricted-water navigation regardless of UMS status.
UMS — Unmanned Machinery Space
Day-manned · Night call-out
Engine room is manned during the day and all manoeuvring. Unmanned during night hours with a designated duty engineer on call. Requires class certification and SOLAS-mandated alarm and automation systems. Legal basis: SOLAS Chapter II-1, Regulations 46–54.
The Chief Engineer does not stand a routine watch in either regime. On UMS vessels the Second Engineer typically manages the duty engineer roster.
How the ranks connect.
The officer track: Engineer Cadet → Fourth Engineer → Third Engineer → Second Engineer → Chief Engineer. Each step requires documented sea service at the current rank, assessed against STCW competence tables.
The ratings track runs in parallel: Wiper → Motorman → Able Seafarer Engine. The Electro-Technical Officer and Electro-Technical Rating are a separate specialist track with their own certification pathway under STCW Regulations III/6 and III/7.
Exam requirements, sea time thresholds and approved programmes are on the pathways pages.
Talk to working engineers.
The Career & Recruitment category on the Marine One forum covers engine department questions — from first steps to chief engineer exams. Read what others have been through, or ask your own question.