To get a mariner’s license — formally called a Merchant Mariner Credential (MMC) from the U.S. Coast Guard — you need to meet age and citizenship rules for the endorsement you want, pass a physical and a drug test, get a TWIC security card, log the required sea service, complete First Aid and CPR training, pass a Coast Guard exam, and pay several hundred dollars in fees. The whole package is submitted to the National Maritime Center (NMC), and a straightforward first-time application usually runs $400 to $600 before any prep courses.
Who Can Apply
Age depends on the endorsement. Entry-level rating jobs and the Operator of Uninspected Passenger Vessels (OUPV) endorsement — the “six-pack” charter captain license — are open at 18. A Master of vessels under 200 gross register tons requires 19. Most other officer endorsements require 21.1eCFR. 46 CFR 11.201 – General Requirements for National and STCW Officer Endorsements
Officer endorsements generally require U.S. citizenship. The main exception is the OUPV endorsement for service on undocumented vessels, which is available to non-citizens.2govinfo. 46 CFR 10.221 – Citizenship Rating endorsements are open to lawful permanent residents and to foreign nationals enrolled at the U.S. Merchant Marine Academy.
Medical Exam, Drug Test, and TWIC
Three separate checks have to clear before the Coast Guard will issue anything.
The physical is documented on Form CG-719K. A licensed medical provider evaluates your vision, color perception, hearing, and general fitness for shipboard duty. Color vision testing needs objective documentation from an optometrist or ophthalmologist. Conditions that affect balance, judgment, or consciousness can lead to denial, so disclose them rather than let them surface later.3United States Coast Guard. Medical Certificate Costs vary by provider, usually $30 to $300. The medical certificate is submitted and reviewed as a separate package from the main credential application.
You also need a negative drug test result dated within the past 185 days for any new or renewed credential. It has to be a DOT-compliant five-panel screen covering marijuana, cocaine, amphetamines, opiates, and PCP. You can document it with Form CG-719P, a federal chain-of-custody form, or an original letter from a marine employer confirming pre-employment or random testing.4United States Coast Guard. Drug Testing The test isn’t required for adding endorsements to an existing credential, for duplicates, or for STCW certificates. Budget roughly $65 to $95.
The Transportation Worker Identification Credential (TWIC) is a TSA-issued security card that grants access to secure areas of maritime facilities and vessels. A five-year TWIC costs $124, or $93 if you already hold a valid CDL with a hazardous materials endorsement or a FAST card.5Transportation Security Administration. Transportation Worker Identification Credential For a first MMC, you can start the application before your TWIC is in hand — proof that you’ve applied is enough to open the file — but the Coast Guard won’t issue your credential until TSA confirms TWIC approval.6U.S. Coast Guard. Application for Merchant Mariner Credential Form CG-719B
Sea Service for the Credential You Want
What you can do on the water depends on which endorsement you qualify for, and each one has its own sea service floor. The two common starting points for aspiring captains are OUPV and Master.
OUPV (Six-Pack)
OUPV authorizes you to operate uninspected vessels carrying six or fewer passengers for hire — think charter fishing, dive boats, and small tours.7United States Coast Guard. Charter Boat Captain You need 360 days of sea service. If you want ocean or near-coastal authority, at least 90 of those days have to be on ocean or near-coastal waters; without them the credential is limited to inland waters.
Master Under 100 or 200 GRT
A Master endorsement lets you command inspected passenger vessels carrying more than six passengers, up to the tonnage limit stamped on your credential. For a Master under 100 GRT, you need 360 days of service in the deck department, with at least 90 on the Great Lakes if you want Great Lakes authority.8United States Coast Guard. National Master of Self-Propelled Vessels Less Than 100 GRT Checklist
Documenting Your Time
For vessels under 200 GRT, the Small Vessel Sea Service Form (CG-719S) captures your days, role, and operating waters. For larger vessels, the Coast Guard accepts service letters, certificates of discharge, or other official documents signed by the vessel’s owner, operator, master, or chief engineer. Every record needs the vessel name and official number, gross tonnage, propulsion type, your position, the dates and routes served, and the waters operated in.9eCFR. 46 CFR 10.232 – Sea Service Vessel owners can attest to their own experience as long as they provide proof of ownership.
Training You’ll Need Before You Apply
Any initial deck or engineer officer endorsement, including OUPV and Master, requires current First Aid and CPR certification. First Aid must have been completed within 12 months of your application date, and CPR has to be valid on the day you apply.10United States Coast Guard. First Aid and CPR Documentation The Coast Guard accepts American Red Cross Standard First Aid and American Heart Association CPR courses, among others; from other providers you’ll need a certificate with the appropriate course code.
Mariners headed for vessels covered by the international STCW Convention may need additional training in firefighting, survival craft proficiency, and security awareness. Those requirements vary with the endorsement and the vessel’s operating profile.
How Criminal History Is Handled
A conviction doesn’t automatically disqualify you, but many offenses trigger an “assessment period” you have to wait out before the Coast Guard will issue a credential. The clock starts when you’re released from incarceration, not the date of conviction, and if you have multiple convictions the longest applicable period controls.11eCFR. 46 CFR 10.211 – Criminal Record Review Typical ranges:
- Intentional homicide: 7 to 20 years
- Sexual assault: 5 to 10 years
- Drug trafficking: 5 to 10 years (original applications only)
- Drug use or possession: 1 to 10 years
- Burglary: 3 to 10 years
Any dangerous drug conviction makes you ineligible unless you can show rehabilitation through evidence like completion of an accredited treatment program, active counseling, character references attesting to sobriety, and steady employment. A drug conviction more than 10 years old is not, on its own, grounds for denial.11eCFR. 46 CFR 10.211 – Criminal Record Review Don’t omit anything: failing to disclose a conviction can be treated as fraud and carry its own one-year assessment period.12National Maritime Center. Mariner Applications and Criminal Records
What It Costs
Coast Guard fees for a new credential:13National Maritime Center. Frequently Asked Questions – Fees
- Original officer endorsement: $100 evaluation + $45 issuance
- Original rating endorsement: $95 evaluation + $45 issuance
- Renewal (any type): $50 evaluation + $45 issuance
If you request multiple endorsements on the same application, you pay only one evaluation fee (the highest applicable) and one issuance fee.
Exam fees are separate and paid before your first sitting: $110 for original officer exams at the unlimited or chief engineer level, $95 for other original officer exams including OUPV, and $45 for renewal or modification exams.
Add the TWIC ($124), the physical ($30 to $300), and the drug test ($65 to $95). A first-time OUPV applicant can realistically expect $400 to $600 in fees and testing before any prep course.
How to Submit and How Long It Takes
The core form is the Application for Merchant Mariner Credential (Form CG-719B). You’ll submit it with TWIC evidence, sea service documentation, drug test results, training certificates, and proof of payment.6U.S. Coast Guard. Application for Merchant Mariner Credential Form CG-719B The medical certificate (CG-719K) travels as its own package.
Applications go through the National Maritime Center’s online portal, or you can work with a Regional Exam Center (REC). RECs are in roughly 20 cities and handle both exam scheduling and application processing.14United States Coast Guard. Merchant Mariner Credential Once the NMC confirms your package is complete and your sea service and training check out, you’ll get an Authorization to Test letter letting you sit for the Coast Guard exam.
As of January 2026, the NMC’s average net processing time — the days the Coast Guard is actively working your file — was about 23 days, and 90% of credentials were produced within 30 days.15National Maritime Center. Monthly Report on Mariner Credentialing Program Performance Total calendar time is usually longer, because most applicants have to respond to at least one request for more documentation. A thorough, error-free first submission is the single biggest thing you control.
Keeping It Current
An MMC is valid for five years from the date of issuance.16eCFR. 46 CFR 10.205 – Validity of a Merchant Mariner Credential You can file a renewal up to eight months before it expires, and the new credential’s start date will line up with the old one’s expiration so you don’t lose any time. You cannot work under an expired credential.
Renewal requires a new medical certificate, a current drug test, and proof of maintained competence, which you can show in one of five ways:17eCFR. 46 CFR 10.227 – Requirements for Renewal
- At least one year of qualifying sea service in the past five years.
- An open-book renewal exercise issued by an REC covering your endorsement’s subject matter.18National Maritime Center. Renewal Exams
- A Coast Guard-approved refresher course.
- At least three of the past five years working in a position closely related to vessel operation, construction, or repair; deck officers on this path also pass a Rules of the Road open-book exercise.
- Evidence that you taught a relevant Coast Guard-approved course at least twice in the past five years.
If your credential has already expired, there’s a 12-month administrative grace period during which you can still renew under the standard process. You cannot serve aboard a vessel during that window; it only keeps the renewal path open. After 12 months, additional requirements kick in to reestablish the credential. Mariners whose credential expired during active military service, with no reasonable opportunity to renew, can add the military service time to the 12-month window.