- What National Mate Unlimited GL and Inland Actually Covers
- How the Exam Modules Are Built
- Rules of the Road: Q100 or Q300
- Deck General (Q308)
- Deck Safety (Q309)
- Navigation General (Q310) and Chart Plot (Q311)
- Great Lakes Topics (Q312)
- Which Modules Apply to Your Route
- Sequencing Your Preparation
- Where This Credential Fits in a Career
- Frequently Asked Questions
- The credential is NMC GLI02, Mate of Unlimited Tonnage Great Lakes and Inland, governed by the U.S. Coast Guard National Maritime Center.
- Great Lakes and Inland routes use Q100 for Rules of the Road; Inland applicants use Q100 unless they request Q300.
- Choosing Q300 produces a geographic COLREGS limitation on the credential.
- Q312 (Great Lakes Topics) applies only to Great Lakes routes; Inland-only routes omit it.
What National Mate Unlimited GL and Inland Actually Covers
National Mate Unlimited GL and Inland (NMUGI) is the examination pathway for the U.S. Coast Guard credential titled Mate of Unlimited Tonnage Great Lakes and Inland, catalogued by the National Maritime Center (NMC) under the code GLI02. This is a mariner licensing examination, not a vendor certification or a multiple-choice quiz run by a private testing company. The governing body is the United States Coast Guard National Maritime Center, and the content you are tested on comes from the NMC's published examination guide.
If you are new to the acronym, the explainers at What Is NMUGI? and What Does NMUGI Stand For? cover the naming in more detail. This article focuses on the certification itself: what the exam modules contain, how they combine for different routes, and how to prepare for the parts that matter to your situation.
How the Exam Modules Are Built
The NMC examination guide presents the content as six heading groups. These are module and topic groups, not percentage weights. The practical consequence is that no domain can be treated as "worth 20 percent" or similar. Each module has to be mastered on its own terms.
| Domain | Module | Applies To |
|---|---|---|
| Rules of the Road: International and Inland | Q100 | Great Lakes and Inland routes; Inland routes by default |
| Rules of the Road: Inland only | Q300 | Inland applicants who request it (produces a COLREGS limitation) |
| Deck General | Q308 | All full initial routes |
| Deck Safety | Q309 | All full initial routes |
| Navigation General Great Lakes and Inland | Q310 | All full initial routes |
| Chart Plot | Q311 | All full initial routes |
| Great Lakes Topics | Q312 | Great Lakes route only |
The six headings treat the Rules of the Road alternatives (Q100 and Q300) as a single preparation area, while Q312 stays distinct because it is route-specific. That is why you will see "six domains" even though seven module codes exist. A given candidate never sits both Rules modules as part of a universal seven-module exam.
For a domain-by-domain breakdown written from the candidate's perspective, see the companion piece NMUGI Exam Domains 2026: Complete Guide to All 6 Content Areas.
Rules of the Road: Q100 or Q300
The first domain is the one where your choice actually changes the credential you receive.
Q100: Rules of the Road, International and Inland
Covers watchkeeping, the International Regulations for Preventing Collisions at Sea (COLREGS), and the Inland Navigational Rules.
- The published examination guide specifies Q100 for Great Lakes and Inland.
- Inland applicants use Q100 unless they specifically request Q300.
- Requires fluency in both rule sets, including where they diverge.
Q300: Rules of the Road, Inland
Covers watchkeeping and the Inland Navigational Rules only.
- Available where an Inland applicant requests it.
- Choosing Q300 produces a geographic COLREGS limitation on the resulting credential.
- Narrower to study, but narrower in what the credential allows.
The trade-off is straightforward. Q300 means less material to learn and a restricted credential. Q100 means broader preparation and no COLREGS limitation. Because a limitation can matter later if you want to widen your route, think about your longer-term plans before requesting Q300. Eligibility details for applicants are covered in NMUGI Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Deck General (Q308)
Q308 is the broadest module in the guide and the one most likely to surprise candidates who prepare only for navigation. Its published topic list spans seamanship, vessel handling, cargo, law, and shipboard management.
Seamanship and Watchkeeping
Marlinspike seamanship, purchases, blocks and tackle, and the basic principles of watchkeeping, including the Navigation Safety Regulations in 33 CFR 164.
- Know 33 CFR 164 requirements as a regulatory topic, not just a seamanship one.
- Expect applied questions on rigging and mechanical advantage.
Vessel Maneuvering and Handling
This is where Great Lakes and river realities show up in the guide.
- Vessel handling in rivers and estuaries; maneuvering in shallow water.
- Interaction with the bank and with passing ships.
- Berthing and unberthing; anchoring and mooring; dragging and clearing fouled anchors.
- Heavy weather operations and ice operations or ice navigation (both flagged with Note 3).
- Turn circle, pivot point, advance and transfer, and the maneuvering characteristics of major vessel types.
- Wake reduction.
Cargo, Law, and Ship's Business
Cargo stowage and security (including cargo gear), loading and discharging operations, dangerous and hazardous cargo regulations, and tank vessel and fuel oil operations. The law and management portion covers national maritime law, credentialing of seamen, shipboard management and training, vessel alteration, repair and hot work, safety, ship's business, and the certificates and documents required.
The breadth of Q308 is its main difficulty. No single topic is exotic, but the list is long, and candidates who skim the cargo and law sections tend to feel it. See How Hard Is the NMUGI Exam? for a discussion of where candidates typically find the material demanding.
Deck Safety (Q309)
Q309 combines stability and construction with firefighting, emergency response, communications, and lifesaving. It is a safety-regulation module in the most literal sense.
- Stability, construction, and damage control: principles of vessel construction, trim and stability, vessel structural members (each flagged with Note 3), and damage control.
- Vessel power plants: marine engineering terms a deck officer is expected to know.
- Fire: prevention and firefighting appliances, organization of fire drills, the classes and chemistry of fire, firefighting systems, equipment and regulations, and basic firefighting and prevention.
- Emergency procedures: temporary repairs, passenger and crew safety in emergencies, fire or explosion, abandon ship procedures, emergency steering, rescuing survivors from a ship or aircraft in distress, man overboard procedures, and emergency towing.
- Communications and signals: storm, wreck, distress, and special signals.
- Lifesaving: lifesaving appliance regulations and lifesaving appliance operation.
Navigation General (Q310) and Chart Plot (Q311)
These two modules are closely related but test different skills. Q310 is conceptual and instrument-oriented; Q311 is the hands-on plotting module.
Q310: Navigation General Great Lakes and Inland
Covers position determination and the supporting systems around it.
- 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.
- Compasses: magnetic and gyro, including principles, operation, maintenance of the gyro compass, and error and correction for both types, plus determination of compass error.
- Terrestrial observation.
- Meteorology and oceanography: weather systems, ocean current systems, weather charts and reports, tides and tidal currents.
- Navigation Safety Regulations (33 CFR 164).
Q311: Chart Plot
Focuses on applying piloting and navigation methods on a chart.
- Piloting, distance off, bearing problems, fix or running fix.
- Chart navigation and dead reckoning.
- Electronic navigation and instruments and accessories.
- Aids to navigation, charts, navigation publications, and Notices to Mariners.
Q311 overlaps heavily with the first half of Q310's topic list, which works in your favor: plotting practice reinforces the conceptual material in Q310. Candidates who do chart work regularly on watch often find Q311 more intuitive than the weather and compass theory in Q310.
Great Lakes Topics (Q312)
Q312 is the route-specific module. It appears only for Great Lakes routes, and Inland-only routes omit it entirely. Its topic list is notable because it re-presents material from other modules through a Great Lakes lens: piloting, distance off, fix or running fix, dead reckoning, meteorology, tides and tidal currents, vessel maneuvering and handling, ice operations, stability and damage control, and cargo handling and stowage, including dangerous cargo and tank vessel and fuel oil operations.
Key Takeaway
Do not treat Q312 as "extra" material. Much of its content overlaps with Q308, Q309, and Q310, so a candidate who has genuinely mastered those modules is already part of the way there. The work in Q312 is applying that knowledge to Great Lakes conditions.
The current indexed NMC matrix corroborates the headings and the Great Lakes-specific footnote 3 that several topics carry. The examination guide itself carries an older publication date; the review date shown is not a new guide edition, so treat the topic lists above as the published baseline.
Which Modules Apply to Your Route
Because module requirements depend on route and existing credentials, it helps to see the scenarios side by side.
| Scenario | Modules Involved |
|---|---|
| Full initial route, Great Lakes and Inland | Six modules: Q100, Q308, Q309, Q310, Q311, Q312 |
| Full initial route, Inland (default Rules) | Five modules: Q100, Q308, Q309, Q310, Q311 |
| Full initial route, Inland (Q300 requested) | Five modules with Q300 in place of Q100, producing a COLREGS limitation |
| Increase from Inland to Great Lakes and Inland | Q312 required; Q100 additionally required if the existing credential has a COLREGS limitation |
The upgrade path is worth noting. Moving from Inland to Great Lakes and Inland is not a full re-examination: Q312 is the core requirement. The extra wrinkle is that anyone holding a credential with a COLREGS limitation (from an earlier Q300 choice) must also take Q100 to remove it. Details on prerequisites sit in NMUGI Requirements 2026.
On costs and timing, this article deliberately does not state a figure. The guide material available does not support a contemporary fee, renewal period, or aggregate exam time, so verify current numbers directly with the NMC. For a general pricing discussion, see NMUGI Certification Cost 2026: Complete Pricing Breakdown, and for scheduling, NMUGI Exam Dates 2026.
Sequencing Your Preparation
Generic study technique matters less here than ordering the modules sensibly. A reasonable sequence for a full Great Lakes and Inland route builds from rules and navigation foundations toward the broad regulatory and route-specific modules:
Rules of the Road (Q100)
- Learn both rule sets and note where they differ.
- Rules knowledge feeds every later module that touches watchkeeping.
Navigation and Chart Plot (Q310, Q311)
- Pair plotting practice with the conceptual material.
- Because the overlap is heavy, study them together rather than separately.
Deck General and Deck Safety (Q308, Q309)
- These are the broadest lists; give them the most calendar time.
- Alternate regulation topics with operational topics to avoid fatigue.
Great Lakes Topics (Q312) and review
- Apply earlier material to Great Lakes conditions.
- Use the Note 3 topics as a checklist for ice, heavy weather, and stability.
For a longer-form preparation plan, the NMUGI Study Guide 2026 goes into more depth, and the NMUGI Cheat Sheet 2026 is useful for last-pass review. To drill questions in a realistic format, use the NMUGI practice tests.
Where This Credential Fits in a Career
A Mate of Unlimited Tonnage license on the Great Lakes and Inland is the credential associated with watchstanding officer positions on larger vessels operating on the Lakes and inland waters. The kinds of operators that crew such vessels include Great Lakes bulk carrier fleets, tug and barge operators on rivers, and tank vessel operators, which is consistent with Q308's emphasis on cargo, tank vessel operations, and ice and shallow-water handling.
This article does not quote salary figures because none are supported by the source material. For earnings context, see NMUGI Salary Guide 2026, and for whether the effort pays off, Is the NMUGI Certification Worth It?. Job-market specifics are collected in NMUGI Jobs.
Frequently Asked Questions
The United States Coast Guard National Maritime Center governs the credential. The scope is NMC GLI02, Mate of Unlimited Tonnage Great Lakes and Inland, and the content follows the NMC's published examination guide.
No. The guide specifies Q100 for Great Lakes and Inland. Inland applicants use Q100 unless they request Q300, which results in a geographic COLREGS limitation. The two are alternatives, not a combined requirement.
No. Q312 (Great Lakes Topics) is route-specific and is omitted on Inland-only routes. It is required when increasing from Inland to Great Lakes and Inland.
Ordinarily six for Great Lakes and Inland (Q100, Q308, Q309, Q310, Q311, Q312) or five for Inland, with Q300 substituting for Q100 if requested. It is never a universal seven-module exam containing both Rules modules.
No. The six headings are module and topic groups from the published guide, not percentage weights. For related questions on scoring, see NMUGI Passing Score 2026 and NMUGI Pass Rate 2026.