A boatswain (often shortened to “bosun” or “bo’sun”) is the senior unlicensed crew member on a ship’s deck department, responsible for maintaining the vessel’s deck, rigging, and equipment while supervising the deckhands who do much of the physical work. Think of the boatswain as the team leader who bridges the gap between the ship’s officers and the working crew on deck.
Where the Boatswain Fits in the Chain of Command
Every ship operates on a strict hierarchy. At the top sits the master (captain), followed by department heads: the chief mate runs the deck side, and the chief engineer runs the engine room. Below the officers are the ratings, the skilled and less-skilled crew members who keep the ship running day to day. The boatswain is the senior rating on the deck side, managing ordinary seamen and deckhands. While the boatswain doesn’t hold an officer’s license, the role carries real authority. Officers set the plan; the boatswain makes sure the crew executes it safely and correctly.
Daily Responsibilities on Deck
The boatswain’s workday revolves around keeping the ship’s exterior and deck spaces in working order. That means overseeing painting, rust removal, cleaning, and the upkeep of all exposed surfaces and stowage areas. It also means inspecting and maintaining deck equipment like winches, cranes, mooring lines, and anchor gear. When supplies, cargo, or scientific equipment need to be loaded, offloaded, or secured, the boatswain directs the operation and ensures everything is stowed properly so it won’t shift at sea.
Docking, undocking, and anchoring are high-stakes moments that require precise coordination. The boatswain leads the deck crew through these evolutions, making sure mooring lines are handled safely and the vessel is secured correctly. Any work that puts crew members over the side of the ship or up in the rigging also falls under the boatswain’s watch.
On many vessels, the boatswain also serves as the small boat officer, maintaining and operating the ship’s smaller craft, including fast rescue boats. That means conducting regular inspections, running training drills, and ensuring the boats comply with Coast Guard regulations.
Training and Supervising the Crew
A large part of the job is teaching. The boatswain evaluates every unlicensed deck crew member, identifies skill gaps, and trains them to meet the standards needed to perform their duties safely. That training covers daily work tasks as well as emergency station assignments, so every crew member knows exactly where to go and what to do if something goes wrong.
Safety enforcement is constant. The boatswain ensures crew members wear proper protective clothing and equipment for hazardous tasks and are dressed appropriately for weather conditions. If someone is chipping paint in the rain or handling heavy mooring lines, the boatswain is the person making sure they’re protected and following correct procedures.
Technical Skills the Job Requires
Boatswains need a deep command of what the maritime world calls “marlinespike seamanship,” the craft of working with rope and line. That includes tying knots like the bowline (used to form a secure loop), the clove hitch (holds under tension), the square knot (also called the reef knot, used for bundling and reefing sails), and the becket bend (for joining two lines of different sizes). It also includes splicing, the technique of permanently joining two lines or forming an eye in the end of a rope by weaving the strands back into each other. Splices are stronger than knots, so boatswains use them whenever time allows.
Beyond ropework, the boatswain must know how to operate anchor windlasses (the mechanical systems that raise and lower the ship’s anchor), capstans, and gypsy heads used for handling heavy lines and wire. Rigging heavy loads, managing underway replenishment operations, and overseeing towing setups all fall within the boatswain’s expected skill set. These are hands-on, physical tasks that require both technical knowledge and the judgment to know when conditions are unsafe.
Maintenance Tracking and Coordination
Modern boatswains do more than turn wrenches and tie knots. They work directly with the chief engineer to log equipment repairs, track ongoing projects, and manage work requests through the ship’s maintenance management system. The boatswain also contributes to the master voyage repair list, a running document of maintenance and repair projects that need attention during or between voyages. Keeping department inventory at sufficient levels, from paint and line to safety gear, is another ongoing responsibility.
How to Become a Boatswain
In the United States, working aboard commercial vessels requires a Merchant Mariner Credential (MMC) issued by the U.S. Coast Guard’s National Maritime Center. The application process involves submitting several forms, including a general application (CG-719B), documented sea service records, a drug test form (CG-719P), and a medical certificate application. You’ll also need a Transportation Worker Identification Credential (TWIC), which requires a separate background check.
Color vision testing is part of the medical screening, and the Coast Guard requires objective, verifiable documentation from an approved test or a report from an optometrist or ophthalmologist. Informal methods won’t be accepted.
Most boatswains work their way up. You typically start as an ordinary seaman or deckhand, accumulate sea service hours, earn progressively higher ratings, and eventually qualify for the boatswain role through a combination of documented experience and training certifications. STCW (Standards of Training, Certification, and Watchkeeping) endorsements, the international standard for mariner qualifications, may also be required depending on the type of vessel and where it operates.
Pay and Job Outlook
The Bureau of Labor Statistics groups boatswains under “sailors and marine oilers.” As of May 2024, the median annual wage for that category was $49,610. Water transportation workers overall earned a median of $66,490, with the lowest 10 percent making under $36,960 and the highest 10 percent earning more than $139,270. Pay varies significantly based on the type of vessel, the employer, and whether the position involves deep-sea, inland, or coastal work. Government and military-affiliated positions often come with additional benefits.
Job growth for sailors and marine oilers is projected at 2 percent from 2024 to 2034, translating to roughly 700 new positions over the decade. That’s slower than average, but steady retirements and the specialized nature of the work mean openings do come up regularly for qualified candidates.
Where Boatswains Work
Boatswains serve on nearly every type of vessel that has a deck crew. That includes commercial cargo ships, oil tankers, tugboats, research vessels (like those operated by NOAA), military support ships, offshore supply vessels, cruise ships, and large private yachts. The work environment and daily rhythm differ depending on the vessel. A boatswain on a research ship might spend weeks at sea supporting scientific missions, while one on a harbor tug could be home every night. What stays constant is the core job: keep the deck department running, keep the crew trained, and keep the ship safe.