- What This Cheat Sheet Covers (and What It Doesn't)
- The Five Module Groups at a Glance
- Rules of the Road: Q100 vs. Q300
- Deck General (Q340) and Deck Safety (Q341)
- Navigation General (Q342)
- Chart Plot (Q343): The Module You Cannot Skip
- Modules That Look Like Extra Domains But Aren't
- Approval, Fees and Scheduling Mechanics
- Sequencing Your Review Around the Five Groups
- Who Uses This Credential
- Frequently Asked Questions
- NM2GI here means National Master 200 GL and Inland, scope GLI05: Master or Mate less than 200 GRT.
- A full-route preparation has five module groups: rules, Deck General, Deck Safety, Navigation General, and Chart Plot.
- Q100 and Q300 are alternatives. Never count them together as two separate requirements.
- Chart Plot (Q343) is required in the full-exam structure. Do not leave it out of your plan.
What This Cheat Sheet Covers (and What It Doesn't)
This one-page-style review is built around a single credential: National Master 200 GL and Inland (NM2GI), governed by the United States Coast Guard National Maritime Center (NMC). The scope code is GLI05, which covers Master or Mate less than 200 GRT on Great Lakes and Inland waters. If you are still orienting yourself on the basics, start with What Is NM2GI? or What Does NM2GI Stand For? and then come back here for the condensed facts.
A cheat sheet is only useful if it is honest about its limits. This article reflects the examination modules and topic matrices that the NMC publishes publicly. It does not reproduce sample questions, it does not imply issuer endorsement, and it does not invent weightings. The NMC publishes no percentage breakdown across these modules in the material reviewed, and neither will this page. For a deeper look at how each content area is organized, see NM2GI Exam Domains 2026: Complete Guide to All 5 Content Areas.
The Five Module Groups at a Glance
The full-route structure for this credential organizes into five preparation groups. These are route-aware, unweighted groups, not a universal count of examinations that applies identically to every applicant. The exact full-route module sets are:
| Route | Module Set | Count |
|---|---|---|
| Great Lakes and Inland | Q100, Q340, Q341, Q342, Q343 | 5 modules |
| Inland | Q100 OR Q300, Q340, Q341, Q342, Q343 | 5 modules |
The five domains map to those modules like this:
- Rules of the Road: Inland and International (Q100), with Inland-only Q300 as an alternative for the applicable restricted route
- Deck General (Q340)
- Deck Safety (Q341)
- Navigation General: Great Lakes and Inland (Q342)
- Navigation Problems: Chart Plot (Q343)
Rules of the Road: Q100 vs. Q300
This is the single most misread point in NM2GI preparation. Q100 and Q300 are alternatives, not two extra domains. The pairing works as follows:
- Great Lakes and Inland uses Q100, the Inland and International rules module.
- Inland may use Q300 when the applicable COLREGS limitation is accepted. Otherwise Q100 applies.
Domain 1: Rules of the Road (Q100 / Q300)
This group tests whether you can apply the navigation rules to meeting, crossing and overtaking situations and recognize what other vessels are signaling or displaying.
- Know which rule set your route uses before you memorize anything. Studying both in parallel on an Inland-only route wastes time.
- Lights, shapes and sound signals are recognition topics. Drill them until identification is automatic.
- Practice working through who is the stand-on vessel and who is the give-way vessel in a described encounter.
- Understand the practical difference between Inland and International rule sets if your route involves Q100.
If you are weighing which rules module belongs to your situation, read your NMC approval carefully and check NM2GI Requirements 2026: Eligibility, Prerequisites & How to Qualify for how route and limitations connect to what you are asked to take.
Deck General (Q340) and Deck Safety (Q341)
These two modules cover the practical seamanship and regulatory backbone of operating a vessel under 200 GRT. They are separate groups, so treat them as separate review blocks even though the subject matter sometimes touches.
Domain 2: Deck General (Q340)
Core seamanship and vessel-operations knowledge that a master or mate needs day to day.
- Vessel handling and general deck practice appropriate to smaller commercial vessels.
- Stability and loading concepts at the level relevant to the vessel class.
- Rope, anchoring and mooring fundamentals and the terminology around them.
- Regulatory and operational basics that govern how a licensed officer runs the deck.
Domain 3: Deck Safety (Q341)
Safety systems, emergency response and the equipment a master is responsible for keeping ready.
- Fire prevention and firefighting equipment and procedures.
- Lifesaving appliances and abandon-ship considerations.
- Man-overboard, collision and grounding response concepts.
- Pollution prevention and the responsibilities that come with the license.
Key Takeaway
Treat Q340 and Q341 as a pair for scheduling, but keep their notes separate. Safety questions reward precise equipment and procedure recall; general deck questions reward broader seamanship reasoning. Mixing the two in one pile of notes blurs both.
Navigation General (Q342)
Q342 is the Great Lakes and Inland flavor of navigation theory. This is the module that ties together how you find your way and keep a safe track on the waters this credential covers.
Domain 4: Navigation General: Great Lakes and Inland (Q342)
Theory and practice of piloting, aids to navigation and the environmental factors that affect a track.
- Charts, publications and how to use them as primary references.
- Aids to navigation: buoys, beacons and the lateral and cardinal conventions you will meet on the route.
- Compass work, including variation and deviation concepts.
- Tides, currents and weather as they affect small-vessel navigation, with attention to Great Lakes and inland conditions.
- Piloting techniques such as bearings, fixes and running fixes in conceptual form.
One caution: do not confuse this module with other navigation-and-general modules in the Q-series. Alternative Rules or Navigation General modules must never be counted together as simultaneous requirements. Your route has one navigation-general module in the full-original structure, and for this scope it is Q342.
Chart Plot (Q343): The Module You Cannot Skip
Chart Plot, Q343, is required in the full-exam structure and must not be omitted. Candidates sometimes treat plotting as a bonus skill they can lean on from the other navigation material. It is not. It is its own module with its own demands.
Domain 5: Navigation Problems: Chart Plot (Q343)
Hands-on chart work: you solve navigation problems by plotting, measuring and computing on a chart.
- Plotting positions from bearings and distances, and laying off courses.
- Working with variation and deviation to convert between true, magnetic and compass courses.
- Distance, speed and time calculations, including estimating arrival.
- Setting a course while accounting for set and drift (current effects).
- Using chart symbols, scales and the tools of plotting accurately and quickly.
Modules That Look Like Extra Domains But Aren't
Searching the NMC pages, you will run into Q-numbers that do not belong in a full-original NM2GI plan. This is the part of the sheet that prevents the most wasted study time.
| Module | What It Is | In Your Full-Original Plan? |
|---|---|---|
| Q100 | Rules of the Road: Inland and International | Yes, unless Q300 applies on the Inland route |
| Q300 | Inland-only rules alternative, when the COLREGS limitation is accepted | Alternative to Q100, never both |
| Q345 | Navigation and Deck General/Safety, a separate Master less than 100 to Master/Mate less than 200 raise-of-grade module | No, separate raise-of-grade route |
| Q346 | Separate OUPV-to-Mate less than 200 route | No, not an extra Master-original module |
The principle behind the table: separate upgrade, raise-of-grade and route-extension modules are not additional full-original-exam domains. If you are a first-time applicant for the Master route, the five groups above are your map. If you are upgrading from a lower credential, your assigned set may look different, and that is exactly why the NMC approval document governs.
Key Takeaway
Before you buy materials or build a schedule, write down the exact module numbers listed on your approval to test. If a Q-number on your approval is not on your study plan, or the reverse, resolve it with the NMC before you invest weeks in the wrong content.
Approval, Fees and Scheduling Mechanics
The mechanics matter as much as the content. The NMC determines the individual's assigned modules, so the practical sequence is: apply, receive your approval, and then test against the modules that approval names. This credential is not something you can simply walk into.
- Eligibility comes first. Review NM2GI Requirements 2026: Eligibility, Prerequisites & How to Qualify to see what you must demonstrate before the NMC will assign you modules.
- Fees are not fixed here. No current fee schedule is established by the material this article draws on, so confirm the current amounts with the NMC rather than relying on a number you read elsewhere. For the cost picture, see NM2GI Certification Cost 2026: Complete Pricing Breakdown.
- Question count and duration are per-module. No single overall question count or total duration applies across the whole credential, so be wary of any source that quotes one blended figure.
- Scoring thresholds are covered in NM2GI Passing Score 2026: Exactly What You Need to Pass. Check the issuer's published information for what applies to each module.
- Testing windows and scheduling are laid out in NM2GI Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
A population-wide pass rate is also not established by the issuer material reviewed here. If you want to understand what is and isn't known, NM2GI Pass Rate 2026: What the Data Shows walks through it without overclaiming.
Sequencing Your Review Around the Five Groups
Study method is a small part of this article on purpose. What matters more is the order you tackle the groups, because the modules build on one another. A reasonable sequence for a five-group route looks like this:
Rules of the Road (Q100 or Q300)
- Confirm which rules module your route uses.
- Lock in lights, shapes and signals first. They are pure recall and everything else is easier once they are automatic.
Deck General (Q340) and Deck Safety (Q341)
- Cover seamanship and safety back to back while the vessel-operations picture is fresh.
- Keep separate notes for each module.
Navigation General (Q342)
- Build the theory layer: charts, aids, compass, tides and currents.
- This is the foundation Chart Plot depends on, so do it before plotting practice.
Chart Plot (Q343)
- Give plotting the most repetition time, since it is a performance skill.
- Finish with mixed review across all five groups.
If you want a fuller method for turning this into a plan, NM2GI Study Guide 2026: How to Pass on Your First Attempt goes deeper, and you can pressure-test your recall against realistic questions on the main practice test site.
Who Uses This Credential
The scope is Master or Mate less than 200 GRT on Great Lakes and Inland waters, which points to the kinds of operations that run vessels in that size range: towing and small commercial passenger operations, excursion and charter services, and other inland and Great Lakes commercial work. The specific employers and role titles vary by region and season, and the credential itself does not guarantee a position. For a closer look at the market, see NM2GI Jobs, and for earnings context see NM2GI Salary Guide 2026: Complete Earnings Analysis. If you are deciding whether the effort pays off for your situation, Is the NM2GI Certification Worth It? Complete ROI Analysis 2026 frames the tradeoffs.
Frequently Asked Questions
The full route is organized into five module groups: Rules of the Road (Q100, or Q300 as an Inland alternative), Deck General (Q340), Deck Safety (Q341), Navigation General (Q342) and Chart Plot (Q343). The number is not a universal count for every applicant, because your NMC approval determines your assigned modules.
No. They are alternatives. Great Lakes and Inland uses Q100, while the Inland route may use Q300 when the applicable COLREGS limitation is accepted. Counting both as requirements is a common mistake.
No. Q343 Chart Plot is required in the full-exam structure and must not be omitted from your preparation plan.
Q345 is a separate raise-of-grade module for moving from Master less than 100 to Master/Mate less than 200, and Q346 is a separate OUPV-to-Mate less than 200 route. Neither is an extra module in the full-original Master route. Whether either applies to you depends on your approval.
The NMC publishes the examination modules and topic matrices publicly, including the Great Lakes and Inland endorsement pages and the GLI05 module listing. Verify against those and against your own approval to test. For broader background on the credential itself, see NM2GI Certification.