Merchant Marine Ranks: A Complete Guide to the Hierarchy at Sea

Author : Salim Yousaf | Published On : 10 Oct 2025

The Merchant Marine is an essential part of global trade and transportation, responsible for moving goods, oil, and passengers across the world’s oceans. While many people are familiar with naval or military ranks, fewer understand the structure and hierarchy of the Merchant Marine Rank. Just like in any professional field, the Merchant Marine follows a clear rank system that defines authority, responsibility, and expertise aboard a vessel. Whether you’re considering a career at sea or simply curious about how merchant ships operate, understanding the ranks in the Merchant Marine provides a fascinating glimpse into maritime life and discipline.

What Is the Merchant Marine?

The Merchant Marine refers to the fleet of commercial ships that carry cargo and passengers during peacetime. Unlike naval ships, which serve military purposes, merchant ships operate under private or national companies to support trade and commerce. However, in times of war or national emergency, the Merchant Marine may be called upon to assist the navy or transport troops and supplies.

A merchant ship typically operates under three main departments:

Deck Department – Responsible for navigation, ship operations, and cargo handling.
Engine Department – Manages propulsion, power generation, and machinery maintenance.
Catering/Steward Department – Ensures food, hygiene, and accommodation for the crew and passengers.

Each department has its own hierarchy of officers and crew, with specific duties ensuring smooth and safe operation of the vessel.

1. Deck Department Ranks

The Deck Department oversees the ship’s navigation, cargo, safety, and communications. It is headed by the Captain (Master), who is the highest authority on board. Below him, several officers and ratings support the daily functioning of the ship.

a. Captain (Master)

The Captain, also known as the Master, is the highest-ranking officer aboard a merchant vessel. The Captain is legally responsible for the ship, its crew, passengers, and cargo. They oversee navigation, ship operations, safety compliance, and communication with shore authorities. The Captain’s authority is absolute at sea, and every decision regarding the ship’s operation rests with them.

b. Chief Officer (Chief Mate)

The Chief Officer is the second-in-command after the Captain and is primarily responsible for cargo operations, deck maintenance, and safety drills. They also supervise the deck crew and ensure that all equipment, including life-saving and firefighting gear, is in top condition.

c. Second Officer (Second Mate)

The Second Officer usually serves as the ship’s Navigating Officer. They are in charge of voyage planning, updating nautical charts, and maintaining navigational equipment. They often stand watch during specific shifts (known as “watchkeeping”) to ensure the ship’s safe passage.

d. Third Officer (Third Mate)

The Third Officer assists in watchkeeping duties and is often responsible for maintaining safety equipment, such as lifeboats and emergency systems. This rank is usually the starting point for newly licensed officers after completing maritime training.

e. Deck Cadet

A Deck Cadet is a trainee officer who is undergoing practical training at sea to gain experience before earning an officer’s license. Cadets learn navigation, cargo handling, and ship operations under the guidance of senior officers.

f. Bosun (Boatswain)

The Bosun is a senior deck rating who supervises the deck crew (able seamen and ordinary seamen). They carry out the maintenance of the ship’s hull, rigging, and deck equipment.

g. Able Seaman (AB)

An Able Seaman is an experienced deck crew member trained in watchkeeping, maintenance, and emergency procedures. ABs assist in steering, mooring, and general deck duties.

h. Ordinary Seaman (OS)

The Ordinary Seaman is a junior deck rating who assists the ABs and Bosun with cleaning, painting, and other maintenance tasks. This is typically an entry-level position.

2. Engine Department Ranks

The Engine Department ensures the ship’s machinery, power systems, and propulsion are functioning efficiently. These officers and ratings work below deck in challenging environments to keep the ship moving smoothly.

a. Chief Engineer

The Chief Engineer is in charge of all engineering operations on the vessel. They manage the ship’s propulsion system, power generation, and maintenance of all machinery. The Chief Engineer’s role is equivalent in rank to the Captain, though they handle the technical side of operations.

b. Second Engineer

The Second Engineer oversees the day-to-day operations of the engine room. They supervise maintenance, fuel consumption, and machinery performance.

c. Third Engineer

The Third Engineer is responsible for auxiliary machinery such as pumps, compressors, and generators. They often stand engine-room watches and report directly to the Second Engineer.

d. Fourth Engineer

The Fourth Engineer assists with routine checks, lubrication systems, and maintenance of smaller machinery. It is usually the first rank for newly qualified marine engineers.

e. Engine Cadet

An Engine Cadet is a trainee learning the practical aspects of marine engineering before obtaining a professional license.

f. Motorman and Oiler

Motormen and Oilers are engine room ratings who assist engineers with machinery maintenance and cleaning. They keep watch over engines and report any irregularities.

g. Wiper

The Wiper is the most junior member of the Engine Department. Their duties involve cleaning the engine room and helping other crew members.

3. Catering and Steward Department Ranks

The Catering Department ensures that the crew and passengers are well-fed and comfortable throughout the voyage.

a. Chief Cook

The Chief Cook is responsible for preparing meals, managing food inventory, and maintaining kitchen hygiene.

b. Steward

Stewards assist in serving food, cleaning living quarters, and maintaining the galley.

c. Messman/Utility Hand

The Messman is an entry-level position responsible for cleaning dishes, assisting the cook, and performing general housekeeping duties.

How Promotion Works in the Merchant Marine

Promotions in the Merchant Marine are based on a combination of experience, certifications, and training. Officers start as cadets, gain sea-time experience, and then complete examinations conducted by maritime authorities. For example, a Deck Cadet can rise through the ranks to become a Captain, while an Engine Cadet can eventually become a Chief Engineer.

Continuous education is vital — seafarers attend refresher courses and safety training programs to stay updated with international maritime standards.

The Importance of the Rank Structure

The rank system aboard merchant ships ensures:

Clear authority and accountability — Everyone knows their responsibilities.
Efficient teamwork — Each rank has a defined role in navigation, engineering, and safety.
Safety and discipline — The hierarchy allows for organized emergency response.

Without a clear chain of command, ship operations would become chaotic, endangering lives, cargo, and the vessel itself.

Conclusion

The Merchant Marine rank structure represents centuries of maritime tradition and professionalism. From the Captain navigating the high seas to the engineers ensuring the engines run flawlessly, every rank plays a vital role in the success of a voyage. The discipline, training, and teamwork that define these roles make the Merchant Marine one of the most respected professions in the world.

For those dreaming of a life at sea, understanding these ranks is the first step toward embarking on a rewarding maritime career filled with adventure, responsibility, and pride.