Who's Who on a Merchant Ship?

Chief Mate

The Chief Mate, sometimes called the First Mate or Chief Officer, is generally the senior deck officer below the Master. Depending on the vessel, the Chief Mate may be heavily involved with cargo operations, stability, deck maintenance, safety, crew assignments, emergency equipment, deck department supervision and watchstanding. On many merchant ships, the Chief Mate manages much of the deck department's daily operation.

A simple way to think of it: the Captain commands the ship. The Chief Mate manages much of the deck department.

Second Mate

The Second Mate is normally a licensed deck officer and watchstander. Traditional responsibilities often include navigation-related work such as passage planning, navigation publications, chart corrections, navigation equipment and bridge watches. Exact responsibilities vary by ship.

Third Mate

The Third Mate is generally the junior licensed deck officer. Duties may include bridge watchstanding, safety equipment, lifeboats, firefighting equipment, emergency gear and deck operations. For many hawsepipers, reaching Third Mate is one of the major steps from unlicensed deck work into the licensed officer ranks.

The Bosun

The Bosun, or Boatswain, is usually a senior unlicensed member of the deck department. The Bosun commonly works closely with the Chief Mate and supervises day-to-day deck work performed by the unlicensed deck crew: mooring, anchoring, painting, maintenance, rigging, cargo-related work, deck machinery and preservation of the ship. The Bosun is an important bridge between the officers and the deck crew, and may have decades of practical shipboard experience.

Able Seafarer (AB)

An Able Seafarer (formerly Able Seaman), usually shortened to AB, is an experienced deck rating. ABs may perform duties such as standing lookout, steering, mooring, anchoring, deck maintenance, cargo work, safety duties and watchstanding. There are different Able Seafarer endorsements, and eligibility depends on qualifying sea service and other requirements. For many deck mariners, AB is the first major step beyond entry level.

Ordinary Seafarer (OS)

The Ordinary Seafarer (formerly Ordinary Seaman), or OS, is an entry-level deck rating. An OS may assist with cleaning, painting, chipping, line handling, deck maintenance, cargo support and general deck work. Do not confuse "entry level" with "unimportant." This is where many professional mariners begin learning how vessels actually operate. An OS can begin building the sea service and practical experience needed for advancement.

Chief Engineer

The Chief Engineer is the senior engineering officer and heads the engine department, responsible for the operation and maintenance of the vessel's engineering systems. That may include main propulsion machinery, generators, fuel systems, pumps, electrical systems, auxiliary machinery, refrigeration, engine-room safety, maintenance programs and engineering personnel.

The Chief Engineer runs the engineering department. The Master remains in overall command of the vessel. This distinction helps new mariners understand how shipboard authority actually works.

First Assistant Engineer

The First Assistant Engineer, often called the First Assistant or "First," is usually the senior assistant engineer. The First often has substantial responsibility for the day-to-day operation and maintenance of engine-room machinery and engineering personnel. On many vessels, the First fills a role in the engine department somewhat comparable to the Chief Mate's management role in the deck department.

Second and Third Assistant Engineers

These are licensed engineering officers. Their specific machinery responsibilities and watch schedules vary by vessel. They may be responsible for engine-room watches, generators, boilers, fuel systems, pumps, auxiliary machinery, and maintenance and repairs. The Third Assistant Engineer is commonly the entry point into the licensed engineering officer ranks.

QMED

QMED means Qualified Member of the Engine Department. QMED is not one single job. It represents qualified engine-department ratings that may perform watchstanding, machinery operation and maintenance duties depending on their endorsements and assignment. A QMED may have substantial mechanical and engine-room experience. For someone entering through the engine department, QMED can be an important step toward greater responsibility and, for those pursuing that path, eventual engineering officer credentials.

Wiper

A Wiper is an entry-level member of the engine department. Wipers typically clean and paint the engine room and equipment and assist with maintenance and repairs. For someone who likes machinery and mechanical work but has little maritime experience, Wiper can be one door into the industry.

The work may not be glamorous. Neither was being an Ordinary Seafarer. Everybody starts somewhere.