- What the National Mate Unlimited GL and Inland Exam Actually Is
- How the Six Headings Map to Real Exam Modules
- Domain 1: Rules of the Road (Q100 or Q300)
- Domain 2: Deck General (Q308)
- Domain 3: Deck Safety (Q309)
- Domain 4: Navigation General Great Lakes and Inland (Q310)
- Domain 5: Chart Plot (Q311)
- Domain 6: Great Lakes Topics (Q312)
- Which Modules Apply to Your Route
- Sequencing Your Preparation Around the Modules
- Frequently Asked Questions
- The six headings are module groups, not percentage weights; the published guide assigns no domain weights.
- Great Lakes and Inland applicants use Q100 for Rules of the Road; Inland applicants use Q100 unless they request Q300.
- Choosing Q300 produces a geographic COLREGS limitation on the resulting credential.
- Q312 Great Lakes Topics applies only to the Great Lakes route and is omitted for Inland-only routes.
What the National Mate Unlimited GL and Inland Exam Actually Is
The National Mate Unlimited GL and Inland (NMUGI) credential is administered by the United States Coast Guard National Maritime Center (NMC). In NMC terms, it corresponds to the GLI02 examination track: Mate of Unlimited Tonnage Great Lakes and Inland. If you are searching for information about a different credential that happens to share the NMUGI acronym, this guide is not it. Everything here concerns the Coast Guard mate examination for unlimited-tonnage service on the Great Lakes and inland waters.
If you are new to the credential itself, start with What Is NMUGI? for the big picture and NMUGI Requirements 2026: Eligibility, Prerequisites & How to Qualify for the qualification side. This article focuses on one question: what content areas does the examination cover, and how should you think about each one?
How the Six Headings Map to Real Exam Modules
The NMC publishes its examinations as numbered modules, each with a defined topic list. For this credential, the relevant modules are Q100, Q300, Q308, Q309, Q310, Q311 and Q312. This guide groups them under six headings so you can plan your preparation:
| Heading | NMC Module | Applies To |
|---|---|---|
| 1. Rules of the Road | Q100 (International and Inland) or Q300 (Inland only) | All routes; Q100 for Great Lakes and Inland |
| 2. Deck General | Q308 | All routes |
| 3. Deck Safety | Q309 | All routes |
| 4. Navigation General Great Lakes and Inland | Q310 | All routes |
| 5. Chart Plot | Q311 | All routes |
| 6. Great Lakes Topics | Q312 | Great Lakes route only |
Notice that the first heading combines two alternative modules. A candidate does not sit both Q100 and Q300 as a universal requirement. The grouping simply keeps both sets of content visible in one preparation area. The practical result is that a full initial route ordinarily contains six modules for Great Lakes and Inland, or five for Inland alone. It is never a universal seven-module exam.
For a broader look at how these modules translate into difficulty, see How Hard Is the NMUGI Exam? Complete Difficulty Guide 2026.
Domain 1: Rules of the Road (Q100 or Q300)
Rules of the Road is the first preparation area, and it comes in two forms. The published examination guide specifies Q100 for Great Lakes and Inland. Inland applicants use Q100 unless they specifically request Q300.
Q100: Rules of the Road, International and Inland
Q100 covers both rule sets, along with watchkeeping.
- Watchkeeping
- COLREGS (the international rules)
- Inland Navigational Rules
Q300: Rules of the Road, Inland
Q300 is the narrower alternative for Inland applicants.
- Watchkeeping
- Inland Navigational Rules
The subtle point many candidates miss is that the two rule sets are close but not identical. Preparation should focus on the places where the international and inland rules diverge, because those are the places an examiner can build discriminating questions. Practice recognizing which rule set a scenario falls under before you decide how a situation is governed. Our NMUGI Cheat Sheet 2026: One-Page Review of Must-Know Facts is a useful quick-reference companion for this module.
Domain 2: Deck General (Q308)
Q308 is the broadest module in the examination, and it rewards candidates who have genuinely operated vessels. It spans seamanship, ship handling, cargo, law and shipboard management. The published topic list is long, so it helps to break it into clusters.
Seamanship and Watchkeeping
The foundation cluster covers practical deck skills and the regulatory frame for keeping a watch.
- Marlinspike seamanship
- Purchases, blocks and tackle
- Watchkeeping basic principles
- Navigation Safety Regulations (33 CFR 164)
Vessel Maneuvering and Handling
This cluster is where inland and Great Lakes operations show their character.
- Vessel handling in rivers and estuaries
- Maneuvering in shallow water
- Interaction with a bank or a passing ship
- Berthing and unberthing
- Anchoring and mooring, including dragging anchors and clearing fouled anchors
- Heavy weather operations
- Turn circle, pivot point, advance and transfer
- Maneuvering characteristics of major vessel types
- Wake reduction
- Ice operations and ice navigation
Cargo Handling and Stowage
Cargo questions blend practical stowage with regulation.
- Cargo stowage and security, including cargo gear
- Loading and discharging operations
- Dangerous and hazardous cargo regulations
- Tank vessel and fuel oil operations
Maritime Law and Shipboard Management
The administrative cluster is easy to underestimate because it feels less "nautical."
- National maritime law
- Credentialing of seamen
- Vessel alteration, repair and hot work
- Safety
- Ship's business
- Certificates and documents required
Several maneuvering items in Q308, including heavy weather operations, maneuvering characteristics of major vessel types and ice operations, carry Note 3 in the NMC guide, a footnote tying them to the Great Lakes route. Candidates on that route should treat these as active exam content rather than background reading.
Domain 3: Deck Safety (Q309)
Q309 groups stability, construction, damage control, firefighting, emergency response and lifesaving. It is the module where a mate's responsibility for the people aboard is tested most directly.
Stability, Construction and Damage Control
- Principles of vessel construction (Note 3)
- Trim and stability (Note 3)
- Vessel structural members (Note 3)
- Damage control
- Vessel power plants and marine engineering terms
Fire Prevention and Firefighting
- Organization of fire drills
- Classes and chemistry of fire
- Firefighting systems
- Firefighting equipment and regulations
- 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
- Emergency towing
Communications and Lifesaving
- Signals: storm, wreck, distress and special
- Lifesaving appliance regulations
- Lifesaving appliance operation
The three stability and construction items marked with Note 3 again point to Great Lakes-specific content. Spend real time on trim and stability, because those topics reward understanding of the underlying principles rather than memorizing definitions.
Domain 4: Navigation General Great Lakes and Inland (Q310)
Q310 is the theory counterpart to the chart plot. Where Q311 asks you to work a chart, Q310 asks you to understand the instruments, publications and natural phenomena behind your navigation decisions.
Navigation and Position Determination
- Piloting, distance off, bearing problems, fix or running fix
- Chart navigation and dead reckoning
- Electronic navigation
- Instruments and accessories
- Aids to navigation
- Charts, navigation publications and Notices to Mariners
Compasses
- Magnetic and gyro compass principles, operation and maintenance
- Gyro compass error and correction
- Magnetic compass error and correction
- Determination of compass error
- Terrestrial observation
Meteorology, Oceanography and Regulation
- Characteristics of weather systems
- Ocean current systems
- Weather charts and reports
- Tides and tidal currents
- Navigation Safety Regulations (33 CFR 164)
Key Takeaway
Compass error is a recurring theme in Q310: the module separately lists gyro error, magnetic error and the determination of error by observation. Treat these as three related skills and practice the arithmetic until the sign conventions are automatic.
Domain 5: Chart Plot (Q311)
Q311 is the practical heart of the examination. It draws on the same navigation topics as Q310 but tests them as applied plotting problems, so it is less about recalling facts and more about producing correct positions and courses under time pressure.
Q311 Plotting Skills
- Piloting
- Distance off
- Bearing problems
- Fix or running fix
- Chart navigation
- Dead reckoning
- Electronic navigation
- Instruments and accessories
- Aids to navigation
- Charts, navigation publications and Notices to Mariners
The best preparation for a plotting module is physical practice with dividers, parallel rulers and a real chart. Reading about a running fix is not the same as constructing one cleanly and checking it for reasonableness. For a structured approach to building these skills across the whole credential, see the NMUGI Study Guide 2026: How to Pass on Your First Attempt, and for how scoring thresholds work, see NMUGI Passing Score 2026: Exactly What You Need to Pass.
Domain 6: Great Lakes Topics (Q312)
Q312 exists specifically for the Great Lakes route. It is not part of Inland-only routes. It is also the module an existing Inland mate must add when increasing a credential from Inland to Great Lakes and Inland.
Its topic list reuses many subjects from the other modules and applies them to Great Lakes conditions:
Navigation and Environment
- Piloting, distance off, bearing problems, fix or running fix
- Chart navigation and dead reckoning
- Instruments and accessories, aids to navigation
- Charts, navigation publications and Notices to Mariners
- Determination of compass error and terrestrial observation
- Meteorology and oceanography, weather systems, weather charts and reports, tides and tidal currents
Maneuvering and Ice
- Vessel handling in rivers and estuaries
- Maneuvering in shallow water
- Interaction with a bank or passing ship
- Berthing, unberthing, anchoring and mooring
- Dragging anchors and clearing fouled anchors
- Heavy weather operations
- Turn circle, pivot point, advance and transfer
- Maneuvering characteristics of major vessel types
- Wake reduction
- Ice operations and ice navigation
Stability, Construction and Cargo
- Principles of vessel construction, trim and stability, structural members
- Damage control
- Cargo stowage and security, including cargo gear
- Loading and discharging operations
- Dangerous and hazardous cargo regulations
- Tank vessel and fuel oil operations
Because Q312 overlaps heavily with Q308, Q309 and Q310 in subject matter, candidates who have prepared those modules thoroughly will find Q312 less foreign than its length suggests. The distinguishing factor is the Great Lakes operating context: weather, ice, shallow-water handling and the vessels that trade there.
Which Modules Apply to Your Route
The single most common source of confusion is the module count. The table below lays out the main scenarios described in the published guide.
| Your Situation | Rules Module | Q312 Required? |
|---|---|---|
| Full initial route, Great Lakes and Inland | Q100 | Yes |
| Full initial route, Inland only | Q100, or Q300 on request (COLREGS limitation) | No |
| Increase from Inland to Great Lakes and Inland | Q100 additionally required if the existing credential carries a COLREGS limitation | Yes |
In practice, that means a full initial Great Lakes and Inland route ordinarily involves six modules, and an Inland-only route involves five. Confirm your exact module list with the NMC before you invest preparation time, since the right set depends on your starting credential. Eligibility details are covered in NMUGI Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Sequencing Your Preparation Around the Modules
Rather than a generic schedule, order your preparation by how the modules depend on one another. The navigation modules (Q310, Q311 and, for Great Lakes candidates, Q312) share a large common core, so learning that core once pays off three times. The sequence below reflects that logic.
Navigation Core (Q310 and Q311)
- Work compass error problems until the sign rules are automatic
- Practice fixes, running fixes and distance-off problems on a physical chart
- Review aids to navigation and Notices to Mariners
Deck General (Q308)
- Cover seamanship, 33 CFR 164 and the maneuvering clusters
- Review cargo, hazardous materials and maritime law
Deck Safety (Q309) and Rules of the Road
- Study stability, firefighting and emergency procedures
- Compare COLREGS and Inland Rules side by side
Great Lakes Topics (Q312) and Review
- Add ice, heavy weather and shallow-water handling for the Great Lakes route
- Run timed practice across all modules
Adjust the order if one area is your weak spot. A working deck officer may find Q308 comfortable and Q311 humbling, while someone newer to plotting will want to move navigation earlier. If you want a wider view of what you are preparing for, see NMUGI Exam Dates 2026: Testing Windows, Deadlines & Scheduling for planning your timeline, and visit the main practice test site to drill questions by module.
Frequently Asked Questions
No. The six headings are module and topic groups, not scoring percentages. The published NMC guide does not assign percentage weights to them, so prepare every module rather than trying to optimize around a supposed weighting.
No. They are alternatives within the same preparation area. Great Lakes and Inland applicants use Q100. Inland applicants use Q100 unless they request Q300, which produces a geographic COLREGS limitation on the credential.
No. Q312 Great Lakes Topics applies only to the Great Lakes route. Inland-only routes omit it, and an increase from Inland to Great Lakes and Inland requires it.
A full initial route ordinarily contains six modules for Great Lakes and Inland, or five for Inland. It is never a universal seven-module exam including both Rules modules.
Read How Hard Is the NMUGI Exam? for difficulty context and NMUGI Pass Rate 2026: What the Data Shows for what is and is not known about outcomes.