- What You're Actually Preparing For
- Read Your Approval to Test First
- The Five Module Groups at a Glance
- Rules of the Road: Q100 or Q300
- Deck General and Deck Safety
- Navigation General for the Lakes and Inland Waters
- Chart Plot: The Module You Cannot Skip
- A Module-Driven Sequencing Plan
- Route Traps That Cost Candidates Time
- Frequently Asked Questions
- NM2GI is the USCG National Maritime Center's GLI05 route: Master or Mate less than 200 GRT, Great Lakes and Inland.
- The full route is five module groups: Q100 (or Q300 for Inland), Q340, Q341, Q342 and Q343.
- Q100 and Q300 are alternatives. Never prepare for them as two separate requirements.
- Chart Plot (Q343) is required in the full-exam structure, so budget serious practice time for it.
What You're Actually Preparing For
National Master 200 GL and Inland (NM2GI) is a United States Coast Guard credential pathway administered through the National Maritime Center (NMC). It falls under the GLI05 scope, which covers Master or Mate less than 200 GRT on the Great Lakes and Inland waters. If you are weighing whether this credential fits your career, start with What Is NM2GI? and NM2GI Requirements 2026: Eligibility, Prerequisites & How to Qualify. This guide assumes you have decided to pursue it and want to know how to prepare efficiently.
The first thing to understand is that NM2GI is not a single test with one blended score. The NMC publishes examination modules, each identified by a Q-number, and your preparation should be organized around those modules. The NMC publicly publishes the modules and the topic matrices behind them, so you are not studying blind. You are studying a published structure.
Read Your Approval to Test First
Before you buy a single reference book, read the approval to test the NMC issued you. The NMC determines each individual's assigned modules. That sentence matters more than anything else in this guide, because the number of modules on the full route is not a universal count of examinations for every applicant.
Three situations commonly create confusion:
- Original Master or Mate less than 200 GRT: The full five-module route described below applies.
- Raise of grade from Master less than 100 GRT: Q345 (Navigation and Deck General/Safety) is a separate raise-of-grade module. It is not an extra domain layered on top of the original-route modules.
- OUPV to Mate less than 200 GRT: Q346 is a separate route. It is not an additional Master-original module.
Separate upgrade, raise-of-grade and route-extension modules are not additional full-original-exam domains. If you see Q345 or Q346 in discussions online, check whether they apply to your situation before adding them to your plan. Candidates who count everything they find as a requirement tend to over-study some areas and under-prepare others.
The Five Module Groups at a Glance
The full-route preparation breaks into five module groups. They are presented here as unweighted, route-aware groups: the NMC publishes modules and topic matrices, but no percentage weighting is established for these groups, and nothing here should be read as a weighting. For a deeper walkthrough of each content area, see NM2GI Exam Domains 2026: Complete Guide to All 5 Content Areas.
| Group | Module | Subject | Route Notes |
|---|---|---|---|
| 1 | Q100 (or Q300) | Rules of the Road: Inland and International | Great Lakes and Inland uses Q100. Inland may use Q300 when the applicable COLREGS limitation is accepted. |
| 2 | Q340 | Deck General | Part of the full-exam structure |
| 3 | Q341 | Deck Safety | Part of the full-exam structure |
| 4 | Q342 | Navigation General: Great Lakes and Inland | Part of the full-exam structure |
| 5 | Q343 | Navigation Problems: Chart Plot | Required in the full-exam structure; must not be omitted |
The two exact full-route module sets are:
- Great Lakes and Inland: Q100, Q340, Q341, Q342, Q343 (5 modules)
- Inland: Q100 OR Q300, Q340, Q341, Q342, Q343 (5 modules)
Notice the "OR." Alternative Rules or Navigation General modules must never be counted together as simultaneous requirements. If you hold an Inland-only route and qualify for Q300, you prepare for one Rules module, not both. The published guide reference for this route is 2.1.2.3, printed page 27.
Rules of the Road: Q100 or Q300
Domain 1: Rules of the Road: Inland and International (Q100)
Q100 is the Rules module used by the Great Lakes and Inland route. Inland-only Q300 is an alternative for the applicable restricted route, and it is available when the applicable COLREGS limitation is accepted.
- Confirm which Rules module your approval lists before studying either one.
- Learn both the Inland and International frameworks if you are on Q100, because the module name signals that both are in play.
- Treat Q300 as a narrower alternative, not a bonus module to take as well.
Rules of the Road is the module where candidates most often lose confidence, because it rewards precision of language. Rather than memorizing rule numbers in isolation, practice reading a situation and identifying which vessels are involved, what their status is, and what each is required to do. Build a habit of asking the same sequence of questions: What is the visibility condition? What is each vessel's status? Is there a crossing, meeting or overtaking situation? Which vessel is the give-way vessel?
If your route allows the Q300 alternative, do not assume it is easier. It is a different module with its own published topic matrix, and the correct choice depends on your endorsement route and the COLREGS limitation, not on perceived difficulty. For a realistic read on difficulty across the whole route, see How Hard Is the NM2GI Exam? Complete Difficulty Guide 2026.
Deck General and Deck Safety
Q340 and Q341 are the two deck modules, and they reward a practical, shipboard mindset. Many candidates with hands-on experience underestimate them because the material feels familiar. The risk is that real-world habits and published examination content do not always match, so study the published topic matrices rather than relying on what you do on your own vessel.
Domain 2: Deck General (Q340)
Deck General covers the working knowledge a master or mate on a smaller vessel is expected to carry: the vessel, its equipment, and the routine operation of both.
- Work through the published topic matrix line by line and mark each item as confident, shaky or unfamiliar.
- Prioritize the unfamiliar items first. Experience-based confidence tends to hide real gaps.
- Practice explaining each topic in plain language. If you cannot, you do not own it yet.
Domain 3: Deck Safety (Q341)
Deck Safety is its own module and should be studied as its own subject, not folded into Deck General.
- Focus on emergency preparedness, lifesaving and firefighting topics as they appear in the published matrix.
- Pay attention to procedures and sequences, because safety questions often hinge on doing things in the right order.
- Revisit this module late in your plan so the material is fresh when you test.
Navigation General for the Lakes and Inland Waters
Domain 4: Navigation General: Great Lakes and Inland (Q342)
Q342 is the regional navigation module, and the regional emphasis is the point. This is where the credential's identity as a Great Lakes and Inland pathway shows up most clearly.
- Study the topics through the lens of the waters you will actually work: lakes, rivers and protected inland waterways rather than open-ocean navigation.
- Understand the aids to navigation, publications and procedures that apply to these waters as listed in the published matrix.
- Connect Q342 concepts to your chart work, since navigation knowledge and chart plotting reinforce each other.
A practical approach is to pair Q342 study sessions with short chart exercises, so the theory becomes something you do rather than something you recite. That pairing pays off directly in the final module on the route.
Chart Plot: The Module You Cannot Skip
Chart Plot (Q343) is required in the full-exam structure and must not be omitted from your preparation. Candidates sometimes treat it as a bolt-on to the knowledge modules. That is a mistake. It is a distinct skill, and skills are built through repetition, not reading.
Domain 5: Navigation Problems: Chart Plot (Q343)
Chart Plot tests your ability to solve navigation problems on a chart, which means working with positions, courses, distances and the tools you use to plot them.
- Practice with real charts and proper plotting tools, not only with mental shortcuts.
- Work problems slowly at first for accuracy, then add time pressure once your method is reliable.
- Check your own work systematically, because small plotting errors compound.
- Keep a log of the error types you make most often and drill those specifically.
Key Takeaway
Schedule Chart Plot practice across several weeks rather than in one block. Plotting accuracy is a motor-and-method skill that improves with spaced repetition, and cramming it the week before testing is the most common way to waste the module.
A Module-Driven Sequencing Plan
You do not need an elaborate methodology here. What you need is an order that respects how the modules relate to each other. The plan below is a six-week example you can compress or stretch depending on your experience and your approval to test. Adjust it if your route differs.
Orient and Rules Foundations
- Read your approval to test and confirm every assigned module.
- Download the published topic matrices for each module on your list.
- Begin the Rules module (Q100 or Q300) because it is dense and benefits from the longest runway.
Rules Depth and Deck General
- Continue Rules practice with scenario-style situations.
- Start Q340 and mark every unfamiliar topic in the matrix.
Navigation General and First Plotting
- Work through Q342 with a Great Lakes and Inland focus.
- Begin short, daily Chart Plot exercises so Q343 starts building early.
Chart Plot Intensive
- Increase plotting volume and track your recurring errors.
- Keep Rules review going in short daily sessions.
Deck Safety and Weak-Spot Repair
- Study Q341 now so it is fresh.
- Return to the topics you marked unfamiliar in Q340 and Q342.
Full Review and Timed Practice
- Take timed practice sets across all assigned modules.
- Do a final targeted pass on your weakest module and your plotting errors.
The logic behind this order is simple. Rules of the Road and Chart Plot are the two modules that most punish last-minute preparation, so they start early and continue throughout. Deck Safety sits late because it is procedural and benefits from recency. You can find practice material to support each stage on the NM2GI practice test site, and a quick reference for last-minute review is available in the NM2GI Cheat Sheet 2026: One-Page Review of Must-Know Facts.
Route Traps That Cost Candidates Time
Beyond the content itself, several structural misunderstandings waste preparation effort. Knowing them in advance is cheap insurance.
- Counting alternatives as requirements. Q100 and Q300 are alternatives, not two extra domains. Preparing for both because a forum post listed both is wasted effort.
- Importing modules from other routes. Q345 and Q346 belong to separate raise-of-grade and OUPV-to-Mate routes. They are not extra Master-original modules.
- Skipping Chart Plot. It is required in the full-exam structure. Omitting it from your plan is not an option.
- Assuming a single universal exam. The NMC assigns modules individually. Your approval to test is the authority, not a generic list.
- Trusting unofficial numbers. No single overall question count, duration, current fee schedule or population pass rate is established for this route in the sources reviewed here. Be skeptical of any site that quotes precise figures without citing the NMC.
If you are trying to budget, note that current fees should be confirmed directly with the NMC rather than taken from a third party. For a framework on thinking about costs, see NM2GI Certification Cost 2026: Complete Pricing Breakdown. For scheduling considerations, see NM2GI Exam Dates 2026: Testing Windows, Deadlines & Scheduling. And if you are curious about why no pass rate is quoted here, NM2GI Pass Rate 2026: What the Data Shows explains what can and cannot be said responsibly.
Frequently Asked Questions
The full Great Lakes and Inland route consists of five modules: Q100, Q340, Q341, Q342 and Q343. The Inland route also has five, using either Q100 or Q300 for the Rules module. Your individual count depends on the modules the NMC assigns in your approval to test.
No. They are alternatives. Great Lakes and Inland uses Q100, while Inland may use Q300 when the applicable COLREGS limitation is accepted. Confirm which one your approval lists and prepare for that module only.
No. Chart Plot (Q343) is required in the full-exam structure and must not be omitted. It is a distinct skill, so strength in the knowledge modules does not substitute for plotting practice.
Q345 is a separate raise-of-grade module for candidates moving from Master less than 100 GRT to Master or Mate less than 200 GRT. Q346 is a separate route for OUPV holders pursuing Mate less than 200 GRT. Neither is an extra module on the full original route, so check your approval before including them.
This guide does not state a single overall question count, duration or passing percentage, because the sources reviewed do not establish one for this route. For what can be said responsibly, see NM2GI Passing Score 2026: Exactly What You Need to Pass, and confirm current details directly with the National Maritime Center.
Once you have your approval to test in hand, the path forward is straightforward: confirm your modules, study the published matrices, sequence your preparation around Rules and Chart Plot, and practice under realistic conditions. If you are still evaluating the credential's career value, Is the NM2GI Certification Worth It? Complete ROI Analysis 2026 and NM2GI Jobs are good next reads, and you can begin working through practice questions at the main NM2GI practice test whenever you are ready.