Merchant Navy Ranks (Merchant Marine) and Uniform Explained

Most cargo ships have three departments. The deck department navigates the ship, handles cargo, keeps the hull and deck equipment in order and looks after safety and lifesaving gear. The engine department runs the main engine, generators, boilers, purifiers, pumps and steering gear. The catering department, often called the galley or steward's department, feeds the crew and keeps the accommodation clean.

Electrical and automation work falls to the electro-technical officer (ETO) where one is carried, and otherwise to the engineers. Passenger ships add a large hotel department with its own ranks, and offshore vessels add roles such as dynamic positioning operators.

On most cargo ships each deck officer below the master keeps a navigational watch, while the master is on call at all times and takes the con in pilotage waters, heavy traffic or bad weather. The watch times below are the traditional pattern on a three-watch ship, and companies vary them.

The chief engineer heads the engine department and answers to the master for the ship's machinery, fuel and technical condition. The second engineer runs the engine room day to day, plans maintenance and directs the other engineers. Third and fourth engineers keep engine room watches or duty periods on unmanned machinery space ships and look after assigned machinery, which commonly includes generators, boilers, purifiers and pumps, though the split varies by company.

Junior engineers and engine cadets work under supervision while they build sea time. In the United States the same ladder is named third assistant engineer, second assistant engineer, first assistant engineer and chief engineer, and US deck officers are third mate, second mate, chief mate and master.

The ETO became a certificated STCW rank under the 2010 Manila amendments. STCW Regulation III/6 covers the ETO on ships with main propulsion of 750 kW or more, and Regulation III/7 covers the electro-technical rating. ETOs maintain high-voltage systems, automation, alarms, navigation and communication electronics, and the ITF wage scale puts the electrical engineer officer on the same pay line as the second officer.

Ratings are the crew members who are not officers. Deck ratings work under the bosun, engine ratings under the second engineer and catering staff under the chief cook or chief steward.

Ranks are company job titles, and the certificate of competency (CoC) decides which ones a person may legally fill. Under STCW, a deck officer in charge of a navigational watch on ships of 500 gross tonnage or more needs a Regulation II/1 certificate, and the chief mate and master of ships of 3,000 gross tonnage or more need Regulation II/2 certificates. On the engine side, Regulation III/1 covers the watchkeeping engineer on ships of 750 kW or more, and Regulation III/2 covers the second and chief engineer on ships of 3,000 kW or more.

Each national administration issues these under its own names. India's Directorate General of Maritime Administration (DGMA), which replaced DG Shipping on 23 June 2026, issues Second Mate, Chief Mate and Master certificates for foreign-going ships and Marine Engineer Officer Class IV, Class II and Class I certificates. The UK's MCA issues Officer of the Watch, Chief Mate and Master certificates and the matching engineer certificates, and the US Coast Guard puts officer endorsements on the merchant mariner credential.

Promotion needs approved sea time, an exam or assessment for the next certificate, a valid medical and the company's appraisal. The STCW minimums for ships of 3,000 gross tonnage or more are 12 months as an officer of the watch before chief mate, and 36 months as a watchkeeping officer before master, reduced to 24 months if at least 12 of them were served as chief mate. The engine side is similar: 12 months as an assistant engineer before second engineer, and 36 months before chief engineer, including 12 months in a position of responsibility while qualified as second engineer.

Sea time is counted in days signed on, not calendar time, and seafarers spend months on leave between contracts. Many officers take considerably longer than these minimums to reach command, and companies decide when a newly certificated officer is given the post.

Merchant navy uniform is set by each company, not by an international rule, and many cargo ships only wear it in port or for formal occasions. Where gold stripes are worn on epaulettes or cuffs, the common convention puts four stripes on the master and chief engineer, three on the chief officer and second engineer, two on the second officer and third engineer and one on the third officer and fourth engineer. Cadets often wear a plain or single narrow stripe, and on some uniforms the master's stripes form a diamond.

Colours between the stripes show the department on lines that keep the tradition. Purple for engineers goes back to the Royal Navy's 1863 colour scheme, which some shipping lines copied. Green is commonly used for electrical officers, white for pursers and hotel officers and red for medical staff. Ratings usually wear company coveralls or working clothes, with no stripes.

Pay rises with each rank because responsibility does. Under the ITF Uniform TCC wage scale from 1 January 2026, minimum monthly totals on covered ships are USD 3,190 for a third officer, USD 3,304 for a second officer, USD 4,094 for a chief officer, USD 5,710 for a chief engineer and USD 6,272 for a master. These are floors for ships under that agreement, and the merchant navy salary guide explains other sources and what pushes pay higher.