The Merchant Mariner Credential

Prerequisites

Read Ways Into the US Merchant Marine first. Forms, fees, processing times and some rules change from year to year: always use the current versions of the forms and checklists on the US Coast Guard National Maritime Center (NMC) website before you apply.

Learning Objectives

• Explain what the Merchant Mariner Credential (MMC) is, and how endorsements decide the work you may do.
• Tell national officer, national rating, STCW and medical endorsements apart.
• List and prepare the documents you need: TWIC, medical certificate, drug test, sea service and training.
• Understand how the Coast Guard counts days of sea service and the waters they were on.
• Follow an application from start to issue, and avoid the common causes of delay.
• Renew a credential and keep it valid.

What the MMC Is

Every US mariner who works on a vessel that needs a credentialed crew holds a Merchant Mariner Credential: the six-pack charter captain, the deckhand on a harbour tug, the AB on a tanker and the master of a container ship. It is issued by the US Coast Guard and is valid for five years.

It replaced several older documents in 2009: the licence certificate, the merchant mariner's document (the old "Z-card"), the certificate of registry and the STCW certificate. Older mariners still talk about their licence and their Z-card; today everything is in one book.

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The MMC looks like a passport with a red cover. Inside, the pages that matter are the endorsements.

Endorsements

The book itself does not let you do anything. The endorsements printed in it set exactly which jobs you may do, on which vessels and on which waters. The diagram below shows a made-up example of how they read.

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Limitations and extras

Officer endorsements carry details that matter:

• Tonnage: for example 25, 50, 100, 200 or 1,600 gross register tons (GRT), or unlimited.
• Route: Inland, Great Lakes and Inland, Near Coastal, or Oceans.
• Sail: "Sail" or "Auxiliary Sail" lets you command sailing vessels; without it you cannot be master of a sailing vessel carrying passengers.
• Assistance towing: needed to tow a disabled boat for hire, as many small-boat captains do.
• Restrictions: for example "Not valid on vessels over 100 GRT" or a named body of water.

Read every line of a newly issued MMC carefully. Errors happen, and it is easier to correct them straight away than years later.

Before You Apply: the Building Blocks

The diagram shows the seven steps. The first four can run in parallel, and the drug test and medical have time limits, so plan the order.

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1. TWIC

The Transportation Worker Identification Credential is a security card issued by the Transportation Security Administration (TSA), not the Coast Guard. You enrol at a TSA centre with ID and fingerprints, and TSA runs a background check. It is valid for five years.

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Most mariners need a TWIC to get unescorted access to secure areas of ports and vessels. The Coast Guard no longer requires a TWIC for every MMC: some mariners who never need access to secure areas, such as many small passenger vessel operators, can apply without one. Check the current rule for your endorsement before you skip it, because many employers require it anyway.

2. Medical certificate

A doctor or other licensed medical professional examines you and completes form CG-719K (or CG-719KE for entry-level ratings with a lower standard). The Coast Guard reviews it and issues a separate medical certificate. The examination covers:

• vision, including colour vision for deck officers,
• hearing,
• general health and any medications or conditions that could impair you at sea,
• physical ability: climbing ladders, lifting, using survival equipment.

A medical certificate for national endorsements is valid for up to five years; for STCW endorsements and for first-class pilots, two years. Conditions such as diabetes, heart disease or sleep apnoea do not automatically disqualify you, but you will need extra paperwork and possibly a waiver. Start early.

3. Drug test

A Department of Transportation five-panel drug test at an approved collection site, usually taken within six months of the application. A mariner already in an employer's random-testing programme can submit a letter from the programme instead.

4. Sea service

This is where most applications go wrong. Sea service is the documented experience the Coast Guard counts towards an endorsement. It comes from:

• Discharges or letters from employers on company letterhead, listing vessel, dates, position and waters.
• Form CG-719S (Small Vessel Sea Service Form) for your own boat or a friend's. If you owned the boat, you sign it yourself and add proof of ownership (registration or documentation). If someone else owned it, the owner or master signs.

5. Training or exam

For most endorsements you need either to pass the Coast Guard exam at a Regional Exam Center (REC), or to complete a Coast Guard approved course that replaces part or all of the exam. Most six-pack and Master candidates take an approved course. STCW endorsements also need specific courses such as Basic Training.

6. Application

Form CG-719B, the application, together with the fee, the training certificates, sea service, proof of citizenship and the other documents. You submit it to a Regional Exam Center, normally by email. Your application then goes to the National Maritime Center.

7. Evaluation and issue

The NMC evaluates your file. It may send an "awaiting information" letter asking for more: answer it fast. Once approved, you take any required exam (if not covered by a course), and the NMC prints and mails your MMC. Track progress on the Coast Guard's Homeport website.

Counting Sea Service

What counts as a day

The Coast Guard counts sea time in days, and a day is not always a day. The diagram below shows the general rules.

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• Small vessels (generally under 100 GRT): a day is at least four hours underway in a 24-hour period. Two short sails on the same day still make one day.
• Larger vessels: a day is an eight-hour working day.
• Two-watch vessels: where the vessel is allowed to run two 12-hour watches, a 12-hour day can count as one and a half days.

Time alongside or at anchor usually does not count, unless you were working as crew on a vessel in service. Being a guest on someone's boat does not count; you must have been serving as crew.

Which waters

The route on your endorsement depends on where your days were. The diagram below shows the zones.

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• Inland: waters shoreward of the boundary lines set in 46 CFR Part 7: bays, sounds, rivers, harbours, the Intracoastal Waterway. These lines are close to, but not always identical with, the COLREGS demarcation lines on your charts.
• Near coastal: ocean waters not more than 200 nautical miles offshore.
• Oceans: beyond 200 nautical miles.
• Great Lakes: counted separately; they can often stand in for inland, and partly for near coastal.

Higher waters count for lower ones: ocean days also count as near coastal, and near coastal days count as inland. The other way round does not work.

Recency

Most endorsements also need some service in the last three years, often 90 days. Old logbooks prove experience; recent days prove you are still current.

Keep a sea-time log

Start a log on your very first day afloat and keep it for ever. For each day record:

Rebuilding years of sailing from memory is slow, and the Coast Guard can refuse days you cannot support.

Marine Inspectors and the Coast Guard's Other Role

The Coast Guard does not only issue credentials. Its marine inspectors inspect commercial vessels, issue each inspected vessel its Certificate of Inspection (COI), witness stability tests and investigate accidents. The crew a vessel must carry and the credentials they must hold are written on its COI.

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If you work on a passenger vessel, expect to meet inspectors and to show your MMC. Working in a position your endorsement does not cover is a violation for you and for the vessel's operator.

Renewal

An MMC is valid for five years, and you can renew it up to eight months before it expires. To renew an officer endorsement you need either:

• one year of sea service in the past five years, or
• an approved refresher course or exam, or other evidence of continued competence set out in the rules.

You also need a current medical certificate and, if required, a TWIC and drug test. If you are ashore for a time and cannot meet the requirements, you can apply for a continuity endorsement that keeps the credential alive without letting you serve.

Let a credential lapse for too long and you may have to start the process again, including the exam.

Worked Example: First MMC for a Six-Pack

Chris has owned a 30-foot sloop on Long Island Sound for six years and wants an OUPV Near Coastal licence to run sailing charters.

1. Log check: Chris's logbook shows 420 days of four hours or more, 110 of them on the ocean south of Long Island, 140 in the last three years. That meets the 360 days, the 90 near-coastal days and the 90 recent days.
2. Paperwork: Chris fills in CG-719S forms for each sailing season, signs as owner, and attaches the boat's documentation as proof of ownership.
3. Course: Chris takes an approved OUPV course over two weekends and passes its exams. The course certificate replaces the Coast Guard exam.
4. First aid and CPR: a one-day course from an approved provider.
5. Medical and drug test: the CG-719K at a local clinic, and a DOT five-panel test the same week.
6. Application: CG-719B with the fee, course certificate, first aid card, sea service forms, ID and proof of citizenship, emailed to the nearest Regional Exam Center.
7. Wait: the NMC asks for one extra page (the boat documentation for an earlier season). Chris answers within a day. The MMC arrives a few weeks later.

Common Mistakes

• Missing hours or waters on the sea service form. The NMC cannot guess. Each line needs dates, hours and waters.
• Letting the drug test or medical go stale while you wait for course dates.
• Counting days as a passenger. Only days as crew count.
• Not reading the issued MMC. A wrong route or missing sail endorsement is easier to fix at once.
• Forgetting the renewal date. Put it in your calendar a year ahead.

Summary

• The MMC is the Coast Guard's single book for all credentialed mariners, valid five years.
• Endorsements, not the book, decide your work: national officer, national rating, STCW and medical.
• Before applying you need a TWIC (in most cases), a medical certificate, a drug test, documented sea service and training or an exam.
• A sea day is four hours on a small vessel, eight on a larger one; the waters set your route.
• Keep a detailed sea-time log from your first day afloat.
• Renew with a year of sea service in five years or a refresher, and do not let the credential lapse.

Check Your Understanding

1. How long is an MMC valid, and which older documents did it replace?

Answer: Five years. It replaced the licence, the merchant mariner's document (Z-card), the certificate of registry and the STCW certificate.

1. Which agency issues the TWIC, and which issues the MMC?

Answer: The TSA issues the TWIC; the US Coast Guard issues the MMC.

1. What is form CG-719K for, and what is CG-719S for?

Answer: CG-719K is the medical evaluation; CG-719S records small-vessel sea service.

1. On a small sailboat, what counts as one day of sea service?

Answer: At least four hours underway in a 24-hour period, serving as crew.

1. How far offshore do near coastal waters extend?

Answer: Up to 200 nautical miles offshore.

1. Do inland days count towards a near coastal endorsement?

Answer: No. Higher waters count for lower ones, not the other way round.

1. What does the Sail or Auxiliary Sail endorsement allow?

Answer: Command of a sailing vessel, for example one carrying passengers for hire.

1. What document tells you what crew an inspected vessel must carry?

Answer: Its Certificate of Inspection (COI).

1. Name two ways to meet the requirements for renewing an officer endorsement.

Answer: One year of sea service in the past five years, or an approved refresher course or exam.

1. Why should you answer an NMC "awaiting information" letter quickly?

Answer: Your application stops until you do, and other documents such as the drug test can go out of date.