The U.S. Merchant Marine is the country’s fleet of civilian-crewed commercial ships that carry cargo and passengers on domestic and international waters, and by federal policy it also stands ready to serve as a naval auxiliary in wartime. As of early 2025, the active U.S.-flagged fleet included roughly 188 oceangoing vessels over 1,000 gross tons.1Office of the Law Revision Counsel. 46 USC 50101 – Objectives and Policy The mariners who crew those ships are civilians, not sailors in the Navy, and they work under a professional licensing system run by the Coast Guard.
What Merchant Mariners Actually Do
Merchant marine vessels are built for specific jobs. Tankers move petroleum and industrial chemicals. Container ships and bulk freighters carry manufactured goods, grain, and heavy machinery. Roll-on/roll-off ships transport vehicles that drive on and off under their own power. Ferries and cruise ships also fall under the merchant marine umbrella. All of these are civilian ships with civilian crews.
Work aboard is divided into three departments. The deck department handles navigation, cargo, and maintenance of the ship’s exterior and bridge equipment. The engine department runs propulsion, electrical generation, and mechanical repairs. The steward department runs the galley and living quarters. Each department has its own officer hierarchy, and crews stand watches around the clock.
The schedule is the part most people underestimate. A typical deep-sea voyage can keep a mariner away from home for 60 to 120 days before shore leave. Pay tends to be higher than comparable shoreside work in part because of that lifestyle.
The National Defense Mission
The Merchant Marine Act of 1936 built the sealift mission into the fleet itself. Vessel plans have to be submitted to the Navy for review so that commercial ships can be converted economically into naval auxiliaries during a war or national emergency.2U.S. Government Publishing Office. Merchant Marine Act, 1936 In every major conflict since World War II, merchant mariners have moved tanks, ammunition, fuel, and food to forward-deployed troops, freeing Navy warships for combat.
Two federal programs keep that capability alive between wars. The Maritime Security Program pays a retainer to owners of up to 60 privately owned, U.S.-flagged ships, in exchange for making those vessels and their commercial transportation networks available to the Secretary of Defense on short notice.3Maritime Administration. Maritime Security Program The Ready Reserve Force takes a different approach. The Maritime Administration maintains 44 government-owned vessels in reduced operating status, each with a skeleton crew of about 10 civilian mariners. Depending on the readiness tier, those ships are expected to be operational and sailing to loading berths within 5 or 10 days of activation.4Maritime Administration. The Ready Reserve Force (RRF)
Merchant mariners also respond to domestic disasters, delivering food, medical supplies, and infrastructure equipment after hurricanes and other emergencies.
How to Become a Merchant Mariner
Working on a U.S. commercial vessel requires two federal credentials, and both involve background checks that take weeks to clear.
Merchant Mariner Credential
The Merchant Mariner Credential (MMC) is issued by the Coast Guard’s National Maritime Center and is the core professional license. You apply using Form CG-719B, which collects identity information, employment history, and the endorsements you’re seeking.5United States Coast Guard. Application for Merchant Mariner Credential (Form CG-719B) A medical exam on Form CG-719K and a Department of Transportation drug screening are mandatory.6National Maritime Center. Merchant Mariner Credential If you’re pursuing an officer endorsement, you also submit Form CG-719S to document the sea service time you’ve accumulated.
The medical exam is not a rubber stamp. The Coast Guard flags certain conditions, including cardiac disease, diabetes, psychiatric disorders, sleep apnea, and chronic use of controlled substances. A condition on that list doesn’t automatically disqualify you, but the National Maritime Center makes the final call based on whether you can work safely at sea.
Transportation Worker Identification Credential
The TWIC card, administered by TSA, is required for unescorted access to secure port and vessel areas. It involves its own security threat assessment. A new TWIC costs $124 and is valid for five years, with a reduced $93 rate for applicants who already hold a hazardous materials endorsement on a commercial driver’s license.7Transportation Security Administration. Transportation Worker Identification Credential (TWIC) Both the MMC and the TWIC have to remain current for you to work.
STCW Basic Safety Training
If you’ll be sailing on a seagoing vessel, an international convention adds a third requirement. The Standards of Training, Certification, and Watchkeeping (STCW) basic training course covers four elements: basic firefighting, personal survival techniques, personal safety and social responsibility, and elementary first aid.8United States Coast Guard. STCW Basic Training Original and Renewal It runs 40 hours over five days and is usually the first certification a new mariner earns. Renewal requires completing the training within the previous five years, or showing 360 days of qualifying sea service plus refresher coursework.
Training and Academy Routes
There’s more than one way in. Some mariners start in entry-level unlicensed positions and work up over years, accumulating sea time and earning endorsements. Others go through a maritime academy.
The U.S. Merchant Marine Academy
Kings Point, in New York, is the federal academy and the only federal service academy whose graduates enter a primarily civilian career. Graduates earn a bachelor’s degree and a Coast Guard license as a deck or engineering officer. The service obligation is significant: at least five years working on U.S.-flagged vessels or in an approved maritime industry role, at least six years maintaining a merchant marine officer license, and at least eight years as a commissioned officer in a reserve component of the armed forces.9U.S. Merchant Marine Academy. Service Obligation Graduates who go directly into active-duty military service can satisfy the sea-service piece that way.
State Maritime Academies
Six state academies offer similar Coast Guard license programs: California State University Maritime Academy, Great Lakes Maritime Academy in Michigan, Maine Maritime Academy, Massachusetts Maritime Academy, SUNY Maritime College in New York, and Texas A&M Maritime Academy.10Maritime Administration. Maritime Academies Cadets can apply for the Student Incentive Payment program, which provides up to $64,000 over four years for tuition, books, uniforms, and living expenses. In exchange, recipients pursue an unlimited-tonnage Coast Guard license and accept a commission in the Navy Reserve’s Strategic Sealift Officer force.11Maritime Administration. The Student Incentive Payment (SIP) Program
What the Job Pays
Pay varies widely depending on the vessel type, your rank, and whether the work is deep-sea, coastal, or inland. Entry-level unlicensed jobs start lower. Experienced officers on deep-sea container ships or tankers can earn well into six figures. The catch is that deep-sea mariners typically work rotations of two to four months aboard followed by a comparable stretch of leave, so an annual salary is compressed into roughly half the calendar year of actual work. Inland and coastal positions offer more predictable schedules but generally pay less than oceangoing jobs. For someone willing to accept the lifestyle, it remains one of the better-paying career paths that doesn’t require a four-year degree at entry level.
Legal Protections If You’re Injured
Merchant mariners aren’t covered by state workers’ compensation systems. They have their own protections, and in some respects those protections go further.
Under 46 U.S.C. ยง 30104, a seaman injured during employment can sue the employer for negligence and has a full right to a jury trial. The statute uses the same framework that applies to railroad worker injury claims.12Office of the Law Revision Counsel. 46 USC 30104 – Personal Injury to or Death of Seamen This is commonly called a Jones Act injury claim.
A separate maritime doctrine called maintenance and cure requires an employer to cover a mariner’s daily living costs and medical bills any time the mariner is injured or falls ill while serving on the vessel. It applies regardless of fault. Maintenance covers basic household expenses like rent and food. Cure covers reasonable and necessary medical treatment until the mariner either returns to duty or reaches maximum medical improvement, meaning doctors don’t expect further recovery. Maintenance and cure kicks in automatically and exists alongside, not instead of, a negligence claim if the employer’s carelessness contributed to the injury.
Veteran Status
One point often causes confusion: today’s merchant mariners are civilians and generally do not earn veteran status through their service. The exception is historical. Under Public Law 95-202, World War II merchant mariners who served between December 7, 1941, and August 15, 1945, were recognized as having performed active-duty service and became eligible for VA benefits including healthcare, home loans, and burial honors. Public Law 105-368 later extended recognition to mariners who served between August 16, 1945, and December 31, 1946, but only for burial benefits. Qualifying individuals or their survivors use DD Form 2168 to obtain a discharge certificate. Surviving spouses of eligible World War II mariners may still qualify for certain dependent benefits.