The engine department ranks of a merchant ship runs from Chief Engineer down to Wiper. STCW Chapter III certificates it at three officer levels: Officer in Charge of an Engineering Watch (Regulation III/1), then Second Engineer Officer and Chief Engineer Officer (Regulation III/2 on ships of 3,000 kW or more, III/3 on ships of 750 to 3,000 kW). Third and Fourth Engineer are company titles held on the same OICEW certificate. Ratings hold Rating Forming Part of an Engineering Watch (III/4, minimum age 16) or Able Seafarer Engine (III/5, minimum age 18). What gates each step is propulsion power and sea service, not the size of the ship.
Who is in the engine department
The engine department runs and maintains the ship’s propulsion, power generation and auxiliary machinery: main engine, generators, boilers, purifiers, pumps, compressors, steering gear and the electrical plant. It works alongside the deck department, which navigates the ship and works the cargo, and on passenger ships alongside the hotel department.
STCW divides engine personnel into two certificated tiers. Officers hold a Certificate of Competency and either stand an engineering watch or manage the department. Ratings hold a Certificate of Proficiency and support the watch and the maintenance work.
The shipowner sets the titles used on board. The flag state sets the certificates, under the Convention. Titles and certificates do not match one to one, and the gap is wider in the engine room than on deck.
Engine department ranks in order
| Rank | Tier | STCW certificate required |
|---|---|---|
| Chief Engineer | Officer, management level | Chief Engineer Officer, III/2 or III/3 |
| Second Engineer | Officer, management level | Second Engineer Officer, III/2 or III/3 |
| Third Engineer | Officer, operational level | OICEW, III/1 |
| Fourth Engineer / Junior Engineer | Officer, operational level | OICEW, III/1 |
| Electro-Technical Officer (ETO) | Officer, operational level | ETO, III/6 |
| Engine Cadet | Trainee officer | Basic training (VI/1) and an approved training record book |
| Fitter | Senior rating | Normally an Able Seafarer Engine |
| Motorman | Rating | III/4 or III/5 |
| Able Seafarer Engine | Rating | Able Seafarer Engine, III/5 |
| Oiler | Rating | RFPEW, III/4 |
| Electro-Technical Rating (ETR) | Rating | ETR, III/7 |
| Wiper | Entry | Basic training (VI/1) |
The Panama Maritime Authority’s certification list uses the same structure: Officer in Charge of an Engineering Watch (III/1), Second and Chief Engineer Officer (III/2 or III/3), Electro-Technical Officer (III/6), and ratings covering Oiler (III/4), Motorman (III/4 or III/5), Able Seafarer Engine (III/5) and Electro-Technical Rating (III/7). Source: Panama Ship Registry, seafarer certification.
Engine officer ranks: three certificates, four titles
Officer in Charge of an Engineering Watch (Regulation III/1) is the first engineer officer certificate, for ships with main propulsion machinery of 750 kW or more. A newly certificated engineer usually joins as Fourth Engineer (Junior Engineer in some fleets) and is promoted to Third Engineer on the same certificate.
Second Engineer Officer is the next certificate, and it is a management-level one. On ships of 3,000 kW or more (Regulation III/2) it requires 12 months of service as OICEW on ships of 750 kW or more, as codified by the US Coast Guard at 46 CFR §11.327. On ships of 750 to 3,000 kW (Regulation III/3) it requires 12 months as an assistant engineer or engineer officer (46 CFR §11.333).
Chief Engineer Officer on ships of 3,000 kW or more requires 36 months as OICEW, or 24 months if at least 12 of them were served as Second Engineer (46 CFR §11.325). On ships of 750 to 3,000 kW it requires 24 months, at least 12 of them while qualified as Second Engineer (46 CFR §11.331).
How engine ranks line up with deck ranks
People often assume the Second Engineer sits level with the Second Officer. The Second Engineer actually sits level with the Chief Officer. On deck, the management level is Master and Chief Officer; in the engine room it is Chief Engineer and Second Engineer.
| Deck | Engine | Certificate level |
|---|---|---|
| Master | Chief Engineer | Management |
| Chief Officer | Second Engineer | Management |
| Second Officer | Third Engineer | Operational |
| Third Officer | Fourth Engineer | Operational |
Some fleets call the Second Engineer the First Engineer or First Assistant Engineer. It is the same certificate under a different title.
Engine certificates follow propulsion power
Deck certificates scale with a ship’s gross tonnage. Engine certificates scale with its main propulsion power. The officer certificates start at 750 kW, and 3,000 kW is the line between the III/2 management certificates and the III/3 ones. A Chief Engineer whose certificate is limited to 3,000 kW cannot sail as Chief on a ship above that power.
The month values in this section are the United States’ codification of STCW Chapter III. They mirror the Convention, and each one is quoted with its regulation. Your certifying administration may add requirements, such as approved courses, written and oral examinations, or service on a particular propulsion type. Check the requirement published by the administration that will issue your certificate.
What each engineer officer does
The duties below are customary shipboard practice. The regulated part is the STCW function each rank is certificated to perform (marine engineering, electrical and electronic engineering, maintenance and repair, and controlling the operation of the ship), at operational level for OICEW and ETO and at management level for Second and Chief Engineer.
The Chief Engineer heads the engine department and answers to the Master for all machinery, fuel and lubricant management, and for the department’s safety and maintenance systems. The Chief plans major maintenance and bunkering, signs off the engine-room records, and does not normally stand a watch.
The Second Engineer is second in command of the department and runs it day to day for the Chief: the work programme, the planned maintenance system and the ratings. The main engine is usually the Second Engineer’s responsibility. On many ships with an unmanned machinery space, the Second works days instead of standing watches.
The Third Engineer is an operational-level watchkeeper, commonly responsible for generators, boilers and the fuel and lubricating oil purifiers.
The Fourth Engineer is the first officer rank a newly certificated OICEW holds, and commonly looks after auxiliary machinery: pumps, compressors, sewage plant and the oily-water separator.
The Electro-Technical Officer is responsible for the electrical, electronic and control systems throughout the ship. The ETO certificate (III/6) came in with the 2010 Manila amendments to STCW, which also created the Electro-Technical Rating (IMO).
The Engine Cadet is an officer under training, sailing against an approved training record book. A cadet works and keeps watch under supervision and does not hold a certificate of competency.
Engine ratings and their certificates
A Wiper is a first-time entrant with STCW basic training (Regulation VI/1). Wipers clean, help with maintenance and build the sea service needed for a watch rating certificate.
An Oiler holds Rating Forming Part of an Engineering Watch, Regulation III/4. The minimum age is 16, and the service requirement is six months at sea, or approved training that includes at least two months at sea (46 CFR §12.609). An Oiler assists the watchkeeping engineer, makes machinery rounds, and keeps up lubrication and readings.
An Able Seafarer Engine holds Regulation III/5. The minimum age is 18. While qualified as an RFPEW, the applicant needs 12 months of engine-department service, or six months plus approved training (46 CFR §12.607). The deck equivalent, Able Seafarer Deck, is codified at 18 months.
Motorman is a title Panama lists against either III/4 or III/5. In practice a Motorman is an experienced engine rating working on machinery maintenance under the engineers.
The Fitter is the senior engine rating and the engine room’s workshop hand, doing welding, machining and fabrication. STCW has no separate Fitter certificate. It is a shipboard appointment, normally held by an Able Seafarer Engine.
An Electro-Technical Rating holds Regulation III/7. The minimum age is 18, with 12 months at sea, or an approved programme that includes at least six months at sea (46 CFR §12.611). The ETR supports the ETO.
How long the progression takes
These are minimum cumulative service periods, not typical timelines. A berth has to be available at each step.
| Step | Minimum service required (46 CFR) | Other conditions |
|---|---|---|
| Wiper to Oiler (RFPEW, III/4) | 6 months at sea, or approved training plus 2 months | Age 16, basic training |
| Oiler to Able Seafarer Engine (III/5) | 12 months engine service, or 6 months plus approved training | Age 18, RFPEW held first |
| Rating to Officer (OICEW, III/1) | 36 months engine-department service at sea, or an approved programme with 12 months at sea; plus 6 months supervised watchkeeping | The approved cadetship route is three times faster |
| OICEW to Second Engineer (III/2) | 12 months as OICEW on 750 kW or more | CoC examination |
| Second Engineer to Chief Engineer (III/2) | 36 months as OICEW, or 24 months including 12 as Second Engineer | CoC examination |
An approved training programme cuts the qualifying sea service for a first officer certificate from 36 months to 12. That makes the engine cadet’s training record book one of the most important documents in the career, and worth keeping complete and signed.
Pay rises at the same certificate steps. See seafarer salary by rank for the figures and their source.
What you need to carry, at every rank
A certificate of competency alone will not get you signed on. Every engine rank sails with the same document set:
| Document | What it does | Who issues it |
|---|---|---|
| Seafarer’s identity and record book (CDC / SIRB / seaman book) | Records identity and sea service | A flag-state administration |
| STCW certificates | Record competence for the rank and machinery | A flag-state administration, on approved training |
| Certificate of competency (officers) | Authorises service at a given rank and power limit | The administration that examined you |
| Medical fitness certificate | Confirms fitness for sea service | An approved medical practitioner |
Engineers often find out late that a certificate of competency from one country does not automatically let them serve under another country’s flag. To sail as an engineer officer on a Panama, Liberia, Bahamas or Palau ship, you need that administration to recognise your national certificate through a Regulation I/10 endorsement of recognition. Panama’s published list covers this for both the deck and the engine department (Panama Ship Registry). See what a flag-state endorsement is and when you need one.
Engine department and deck department
The two ladders are separate. Sea service in one does not count toward a certificate in the other. The deck side is covered in deck department ranks explained.
Where Seaman Books fits
Seaman Books is the maritime documentation arm of Atomiq Management Consultancies EST., an ISO 9001:2015 certified consultancy operating from #903 Regal Tower, Business Bay, Dubai since 2011.
We prepare, verify and coordinate seafarer documentation with IMO/ILO-ratified flag-state administrations including Panama, Palau, Liberia, Bahamas, Belize, Honduras and St Kitts & Nevis. We also arrange STCW certification and offshore training with accredited centres.
Seaman Books is a documentation support and processing partner. We are not a flag-state authority, we do not issue documents or certificates of competency ourselves, and we cannot guarantee a government outcome.
Check Seaman Book Eligibility Fast
If you are not sure which documents your rank requires, run the free eligibility check with your rank, flag and joining date, or message the Business Bay team on WhatsApp at +971 55 458 3416. Office hours are 09:30 to 18:00 GST.
Frequently asked questions
What are the ranks in the engine department?
From highest to lowest: Chief Engineer, Second Engineer, Third Engineer, Fourth Engineer, Electro-Technical Officer and Engine Cadet, then the ratings: Fitter, Motorman, Able Seafarer Engine, Oiler, Electro-Technical Rating and Wiper. Officers hold certificates of competency under STCW Chapter III. Ratings hold certificates of proficiency under Regulations III/4, III/5 and III/7.
Is a Second Engineer the same level as a Second Officer?
No. On ships of 3,000 kW or more, the Second Engineer holds a management-level certificate under STCW Regulation III/2 and ranks with the Chief Officer. The Second Officer holds an operational-level watchkeeping certificate and ranks with the Third Engineer.
What is the difference between a Third Engineer and a Fourth Engineer?
Both hold the same certificate, Officer in Charge of an Engineering Watch under Regulation III/1. The company decides how machinery and watch duties are split. A Third Engineer commonly looks after generators, boilers and purifiers, and a Fourth Engineer commonly looks after auxiliary machinery.
How long does it take to become a Chief Engineer?
For ships of 3,000 kW or more, 36 months as OICEW on ships of 750 kW or more, or 24 months if at least 12 were served as Second Engineer, as codified at 46 CFR §11.325. Reaching OICEW first takes 36 months of engine service, or an approved programme with 12 months at sea.
What is the lowest rank in the engine department?
Wiper, an entry position that needs STCW basic training under Regulation VI/1. The first certificated engine rank is Oiler, which requires a Rating Forming Part of an Engineering Watch certificate (III/4), a minimum age of 16, and six months of sea service.
What is the difference between an Oiler and a Motorman?
An Oiler holds the engine watch rating certificate, Regulation III/4. Motorman is a title Panama lists against either III/4 or III/5, used for an experienced engine rating working on maintenance. A Motorman who holds III/5 is qualified as an Able Seafarer Engine.
Is a seaman the same as a marine engineer?
Not exactly. “Seaman” or “seafarer” covers everyone who works on board. A marine engineer is an engine-department officer with a certificate of competency under STCW Chapter III. Wipers, oilers and motormen work in the engine department but are ratings, not certificated engineer officers.
Can I use my certificate of competency on a foreign flag ship?
Not on its own. The ship’s flag state has to recognise your certificate through a Regulation I/10 endorsement of recognition. Panama lists endorsements of recognition for engine certificates as well as deck certificates. Apply before you are due to join the ship.
Certification requirements on this page come from the IMO STCW Convention framework, the Panama Maritime Authority’s published seafarer certification list, and the United States’ codification of STCW Chapter III at 46 CFR Parts 11 and 12, each linked in the text. National administrations may add requirements to the Convention minimum, so confirm with the administration issuing your certificate. Seaman Books is a documentation consultancy. It is not a flag-state authority, a certifying body or a training provider of record.
