NM1GI Certification

What This Credential Actually Is

National Master 100 GL and Inland (NM1GI) is a mariner credential administered by the United States Coast Guard National Maritime Center (NMC). It corresponds to the NMC examination listing coded GLI06, which covers Master or Mate on vessels of less than 100 gross register tons (GRT). On this site, "NM1GI" always refers to that specific credential and nothing else.

Because the NMC publishes its examination structure as a set of modules rather than a single monolithic test, the way to think about this credential is as a bundle of subject areas tied to your route. There is no single universal NM1GI paper that every candidate sits in the same form. That route-dependence shapes everything below, from what you study to which modules appear on your approval.

If you are still orienting yourself, the explainers at What Is NM1GI? and What Is NM1GI Certification? cover the basics, and NM1GI Requirements 2026: Eligibility, Prerequisites & How to Qualify walks through qualification.

The Five Route-Aware Preparation Groups

For full-route preparation, the published module and topic catalog resolves into five groups. The Rules group is counted once, even though two different Rules modules exist, because you are assigned one according to your approved route.

For a deeper domain-by-domain walkthrough, see NM1GI Exam Domains 2026: Complete Guide to All 5 Content Areas.

Why Your Approved Route Changes the Content

The "GL and Inland" in the credential name is not decoration. The NMC's module table distinguishes Great Lakes-and-Inland applicability from Inland-only applicability, and certain topics carry a footnote 3 marking them as Great-Lakes-specific. Two topics in the Deck General catalog are flagged this way:

• Heavy Weather Operations
• Maneuvering for Launching of Lifeboats and Liferafts in Heavy Weather

If your approved route is Inland only, these may not apply to you in the same way. If your route includes the Great Lakes, you should expect to be accountable for them. The practical consequence: do not simply study the entire topic list at equal depth. Confirm your route on your approval first, then allocate time accordingly.

Rules of the Road: Q100 or Q300

The Rules group is the one place where the module itself changes with your route. Depending on approval, you are assigned either the combined International and Inland module (Q100) or the Inland module (Q300). The catalog lists three topic areas under this group: Watchkeeping, COLREGS, and Inland Navigational Rules.

Candidates frequently blur the two rule sets, particularly on points where inland and international rules diverge. Build a habit of asking, for every rule you memorize, "which rule set is this from?" That discipline pays off most for Q100 candidates, who must keep both frameworks distinct in their heads.

Deck General (Q347) and Deck Safety (Q348)

Deck General (Q347)

Deck General is the broadest seamanship group, and its catalog reads like a working description of small-vessel operations. The published topics include:

• Seamanship and marlinspike seamanship, plus purchases, blocks, and tackle
• Vessel maneuvering and handling, including handling in rivers and estuaries, maneuvering in shallow water, and interaction with a bank or passing ship
• Berthing, unberthing, anchoring, and mooring, including dragging anchors and clearing fouled anchors
• Heavy weather operations and maneuvering for launching lifeboats and liferafts in heavy weather (the Great Lakes-specific items noted above)
• General handling concepts: turn circle, pivot point, advance and transfer, and wake reduction
• Maritime law, including national maritime law and credentialing of seamen
• Shipboard management and training: ship sanitation, vessel alteration/repair/hot work, safety, ship's business, and certificates and documents required

Deck Safety (Q348)

Deck Safety groups the topics most directly tied to protecting the vessel and the people aboard. The catalog covers:

• Watchkeeping basic principles
• Stability, construction, and damage control: principles of vessel construction, plus trim and stability
• Vessel power plants: small engine operations and maintenance
• Fire prevention and firefighting appliances: organization of fire drills, classes and chemistry of fire, firefighting systems, and basic firefighting and prevention
• Emergency procedures: collision, temporary repairs, passenger and crew safety in emergencies, fire or explosion, abandon-ship procedures, rescuing survivors from a ship or aircraft in distress, man overboard procedures, and emergency towing
• Communications and signals: storm, wreck, distress, and special signals

The emergency-procedures cluster rewards scenario thinking. Rather than memorizing a list, practice walking through a sequence: what happens first, what you communicate, and what you do about the vessel's condition. Stability and fire topics, by contrast, reward understanding the underlying principles, such as the classes and chemistry of fire, because they underpin the practical answers.

Navigation General (Q349) and Chart Plot (Q350)

Navigation General: Great Lakes and Inland (Q349)

This group is the conceptual and instrument-heavy half of navigation. Its catalog includes:

• Navigation and position determination: piloting, distance off, bearing problems, fix or running fix, chart navigation, dead reckoning, and electronic navigation
• Instruments and accessories, and aids to navigation
• Charts, navigation publications, and Notices to Mariners
• Compasses: magnetic and gyro, principles of the magnetic compass, magnetic compass error and correction, determination of compass error, and terrestrial observation
• Meteorology and oceanography: characteristics of weather systems, weather charts and reports, and tides and tidal currents

Navigation Problems: Chart Plot (Q350)

Chart Plot is the applied counterpart. Its published topics overlap with the navigation-general list: piloting, distance off, bearing problems, fix or running fix, chart navigation, dead reckoning, electronic navigation, instruments and accessories, aids to navigation, and charts, publications, and Notices to Mariners.

Because Q350 is a hands-on skill, reading about plotting is not enough. You need repetition with actual plotting tools until fixes, running fixes, and distance-off problems become mechanical. The conceptual reading for Q349, such as compass error and tidal currents, directly feeds the corrections you apply during plots.

Where Q352 Fits and Where It Does Not

The NMC separately lists Q352, Navigation and Deck General/Safety, as a raise-of-grade route module. It is easy to misread this, so a few clarifications help:

• Q352 is not a universal sixth group appended to every full-original examination.
• Q352 is not a second Rules subject.
• Whether Q352 applies to you depends on your route and your approval to test.

If you are working toward a raise of grade rather than an original credential, check whether Q352 appears on your approval. If it does not, it is not part of your plan. If you are pursuing the original credential, the five groups above are your frame of reference, again subject to your approval.

Approval to Test, Fees and Scheduling Mechanics

This is where many candidates go wrong: they treat a blog article, or even the NMC's published guide, as the final word on what they will sit. It is not. Your individual approval to test from the NMC controls the assigned modules, the applicable route, and any credit you may receive.

A few points grounded in the published sources:

• The NMC Examination Guide referenced for this credential reflects regulations effective 2014-03-24. It should be used alongside the current published NMC module-topic index and your own approval, and not as a brand-new 2026 universal exam specification.
• No single mandatory common examination exists here. The groups are route-aware, so two candidates can have different module assignments.
• The sources used for this article do not publish exam fees, passing scores, or pass rates, so none are stated here. For cost and scoring context, see NM1GI Certification Cost 2026: Complete Pricing Breakdown and NM1GI Passing Score 2026: Exactly What You Need to Pass, and confirm current figures directly with the NMC.

Sequencing Your Preparation

Generic study advice is not the point here, but sequencing matters because the groups depend on each other. A sensible order for a full-route candidate looks like this:

Navigation sits last because Q350 plotting benefits from everything before it, and because plotting speed only comes from late-stage repetition. For a fuller plan, the NM1GI Study Guide 2026: How to Pass on Your First Attempt goes deeper, and the NM1GI Cheat Sheet 2026: One-Page Review of Must-Know Facts works well as a final-week refresher. To test yourself against realistic questions as you move through each group, use the NM1GI practice tests.

Where the Credential Gets Used

A Master or Mate credential for vessels under 100 GRT on Great Lakes and inland waters is a working license, so its value shows up in the operators who need licensed deck officers on smaller vessels. Generally that means operators of smaller commercial vessels on inland rivers, harbors, and Great Lakes waters, where a licensed master or mate is required to run or relieve on the vessel.

Specific employer names, pay figures, and demand statistics are not part of the published NMC sources, so this article does not quote any. For earnings context and career framing, see NM1GI Salary Guide 2026: Complete Earnings Analysis, NM1GI Jobs, and Is the NM1GI Certification Worth It? Complete ROI Analysis 2026.

When you are ready to move from reading to drilling, head to the main NM1GI Exam Prep practice site and work through questions organized by these same groups.

Frequently Asked Questions