- What National Master 100 NC (NM1N) Actually Covers
- The Five-Module Map: Q100, Q160, Q161, Q162, Q163
- Q100: Rules of the Road, International and Inland
- Q160: Deck General
- Q161: Deck Safety and Stability
- Q162 and Q163: Near Coastal Navigation and Chart Plot
- Route Awareness: Not Every Candidate Tests the Same Modules
- Sequencing Your Preparation by Module
- Approval to Test and Where to Verify Details
- Frequently Asked Questions
- NM1N is the USCG National Maritime Center's Master Near Coastal under 100 GRT exam, built from modules Q100, Q160, Q161, Q162 and Q163.
- Q165 is a separate OUPV-to-Master raise-of-grade module and is not part of the original five.
- Stability questions live inside Q161, alongside damage control, vessel construction and emergency procedures.
- Q162 and Q163 split navigation theory from hands-on chart plotting, so train both skill types.
What National Master 100 NC (NM1N) Actually Covers
National Master 100 NC (NM1N) refers to the Master Near Coastal, less than 100 GRT, examination administered under the United States Coast Guard National Maritime Center (NMC). This is a mariner credential exam, so everything about it is shaped by federal regulation, published NMC module catalogs and the approval process the NMC runs for each applicant.
That framing matters because it changes how you should study. This is not a single multiple-choice test with a uniform blueprint. It is a set of modules, each drawn from a published topic catalog, and the combination you sit depends on your route. The original full Master Near Coastal under 100 GRT examination uses five modules: Q100, Q160, Q161, Q162 and Q163. If you want the big-picture definition before going deeper, start with What Is NM1N? and then come back here for the preparation plan.
The Five-Module Map: Q100, Q160, Q161, Q162, Q163
The cleanest way to organize your preparation is by the five modules themselves. Older split headings such as separate "Deck General Part I / Part II" or standalone "Stability Problems" blocks belong to a different larger-vessel pattern and should not shape your study plan here. For NM1N, stability material is part of Q161.
| Module | Domain Name | Core Character |
|---|---|---|
| Q100 | Rules of the Road: International and Inland | Watchkeeping, COLREGS, Inland Navigational Rules |
| Q160 | Deck General | Seamanship, maneuvering, fire, lifesaving, communications, ship's business |
| Q161 | Deck Safety | Stability, construction, damage control, emergencies |
| Q162 | Navigation General: Near Coastal | Piloting, compasses, weather, tides and currents |
| Q163 | Navigation Problems: Chart Plot | Position determination, fixes, dead reckoning on the chart |
For a deeper domain-by-domain breakdown, see NM1N Exam Domains 2026: Complete Guide to All 5 Content Areas. The sections below focus on what each module demands of you in practice.
Q100: Rules of the Road, International and Inland
Domain 1: Rules of the Road: International and Inland (Q100)
The published topic catalog for this module lists watchkeeping, COLREGS and the Inland Navigational Rules. The challenge is not memorizing rule numbers in isolation but knowing which regime applies where and how the two differ.
- Know the boundary between the International and Inland rule sets and what changes when you cross it.
- Practice lights, shapes and sound signals until you can identify them from a description instantly.
- Work through stand-on and give-way logic for crossing, overtaking and head-on situations.
- Review watchkeeping principles as the rules frame them, not just as general good practice.
Q100 also carries extra weight in another way: for the published increase-in-scope pathway (Great Lakes or Inland to Near Coastal), Q100 is added to Q160 and Q162 where a COLREGS limitation applies. Even if your route does not include it as a standalone module, the rules knowledge underpins your navigation judgment everywhere else.
Q160: Deck General
Q160 is the broadest module in the set, and the published catalog shows why. It spans seamanship, collision response, marlinspike seamanship, temporary repairs, purchases, blocks and tackle, communications, vessel power plants, lifesaving, firefighting and a long list of operational topics.
Domain 2: Deck General (Q160)
Think of this module as the working knowledge of running a small commercial vessel day to day and in an emergency.
- Maneuvering and handling: turn circle, pivot point, advance and transfer, and wake reduction.
- Seamanship skills: marlinspike work, purchases, blocks and tackle, and temporary repairs.
- Emergency response: collision, fire or explosion, abandon ship procedures, passenger and crew safety, and rescuing survivors from a ship or aircraft in distress.
- Firefighting: classes and chemistry of fire, basic firefighting and prevention, and firefighting appliances.
- Lifesaving and survival: lifesaving appliance operation, survival at sea and emergency procedures.
- Administration and communications: certificates and documents required, ship's business, radiotelephone communications and storm, wreck, distress and special signals.
Because Q160 is so wide, candidates often underestimate it. Build a checklist from the published topic list and tick each item off only when you can explain it without notes. The topics that look "easy" (certificates and documents, ship's business) are exactly where careless point loss happens.
Q161: Deck Safety and Stability
Q161 is where stability lives for this credential. The published catalog lists stability, construction and damage control alongside trim and stability, principles of vessel construction, man overboard procedures and emergency towing.
Domain 3: Deck Safety (Q161)
This module blends conceptual understanding with applied safety response. Several topics overlap with Q160, so expect to see familiar themes approached from the safety and damage-control angle.
- Trim and stability: understand how weight, free surface and flooding change vessel behavior.
- Principles of vessel construction: know the structural terms and how construction affects damage tolerance.
- Damage control: priorities and actions after flooding or structural damage.
- Man overboard procedures: the sequence of actions and maneuvering considerations.
- Emergency towing: preparation, connection and risks.
- Fire or explosion, abandon ship, and rescuing survivors from a ship or aircraft in distress.
- Vessel power plants and small engine operations and maintenance as they relate to safe operation.
Q162 and Q163: Near Coastal Navigation and Chart Plot
Navigation is split into two modules that test different skills. Q162 is the knowledge side; Q163 is the plotting side. They share a core of piloting and position-determination topics, but Q162 adds compasses, weather and tides while Q163 adds electronic navigation and chart work.
Q162: Navigation General, Near Coastal
Domain 4: Navigation General: Near Coastal (Q162)
This module covers the theory and instruments behind safe near coastal navigation.
- Piloting, distance off, bearing problems, fix or running fix, dead reckoning and chart navigation.
- Instruments and accessories, aids to navigation, and charts, navigation publications and Notices to Mariners.
- Compasses: principles of the magnetic compass, magnetic compass error and correction, determination of compass error, and gyro basics.
- Terrestrial observation techniques.
- Meteorology and oceanography: characteristics of weather systems, ocean current systems, weather charts and reports, and tides and tidal currents.
Q163: Navigation Problems, Chart Plot
Domain 5: Navigation Problems: Chart Plot (Q163)
Here you demonstrate the skill, not just the knowledge. Expect to work position-determination problems on a chart.
- Fix or running fix, bearing problems, distance off and dead reckoning plotted accurately.
- Piloting and chart navigation using aids to navigation and chart information.
- Electronic navigation concepts as they appear in the published topic list.
- Correct use of instruments, chart symbols and Notices to Mariners.
Chart plotting rewards repetition more than any other part of NM1N. Reading about a running fix is not the same as plotting five of them cleanly. If you want a sense of how candidates experience the plotting portion, How Hard Is the NM1N Exam? covers where difficulty tends to concentrate.
Route Awareness: Not Every Candidate Tests the Same Modules
One of the most common misunderstandings is treating NM1N as one fixed exam that everyone takes in full. The published NMC material describes several pathways, and you should not add them together.
| Pathway | Published Module Pattern |
|---|---|
| Original Master Near Coastal under 100 GRT (full exam) | Q100, Q160, Q161, Q162, Q163 |
| Increase in scope from Great Lakes/Inland to Near Coastal | Q160 and Q162, plus Q100 where a COLREGS limitation applies |
| OUPV-to-Master Near Coastal under 100 raise of grade | Q165 (Navigation and Deck General/Safety), a separate module |
Two cautions follow from this. First, do not add Q165 to the original five; it belongs to the raise-of-grade route only. Second, do not sum alternate upgrade pathways into one giant syllabus. Your evaluation from the NMC determines what you actually test, so confirm it before you plan your study hours. Eligibility questions are covered in NM1N Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Key Takeaway
Identify your route first, then build your module list. Studying material for a pathway you will not test wastes time, and skipping a module you will test is far worse.
Sequencing Your Preparation by Module
Because official percentage weights are not published, the groups below are unweighted, route-aware preparation blocks rather than a ranking of importance. A sensible order for the full five-module route puts foundation material first and skill-heavy plotting in the middle, with a closing integration pass.
Q100 Rules of the Road
- Learn lights, shapes and signals, then both rule sets side by side.
- Drill crossing, overtaking and head-on scenarios until the logic is automatic.
Q162 and Q163 Navigation
- Start plotting early: fixes, running fixes, distance off and dead reckoning.
- Layer in compass error, weather, currents and tides alongside daily plots.
Q160 Deck General and Q161 Deck Safety
- Work through the published topic lists module by module, covering seamanship, firefighting, lifesaving and communications.
- Study stability, damage control and construction together inside Q161.
Integration and Review
- Take full practice sets across all modules and revisit weak topics.
- Redo timed chart plots to confirm accuracy under pressure.
The reason navigation comes early is practical: plotting skill develops slowly, so starting it while your schedule is still open pays off later. Rules of the Road comes first because it feeds directly into navigation judgment. Adjust the pacing to your own timeline; the point is the order, not the exact week count. For a compact reference you can review in the final days, keep the NM1N Cheat Sheet handy.
Approval to Test and Where to Verify Details
Mariner credentialing runs through the NMC, and your ability to sit modules depends on individual approval. Do not assume a universal fee schedule, a universal timer or a single nationwide exam calendar applies to every candidate. The published material does not give one, and fabricating one would mislead you.
For cost context, read NM1N Certification Cost 2026: Complete Pricing Breakdown, and for scheduling considerations see NM1N Exam Dates 2026: Testing Windows, Deadlines & Scheduling. Scoring expectations are discussed in NM1N Passing Score 2026: Exactly What You Need to Pass.
The authoritative sources are the NMC's own pages: the ONC06 Master Less Than 100 GRT module pages for Q100/Q161 and Q162/Q165, and the NMC examination guide PDF. Check them directly before you commit to a plan, since module details can be updated by the NMC.
Turning Preparation Into Practice
Reading the catalog is only the first step. The modules reward active recall: explaining a stability concept aloud, plotting a fix from scratch, or identifying a light pattern without a reference. When you are ready to test yourself against realistic question styles, use the NM1N practice test site to find your weak modules, then return to the relevant section above and rework that material. Repeat the cycle until your practice results are consistent rather than lucky.
If you are weighing whether the credential fits your career goals, Is the NM1N Certification Worth It? and NM1N Jobs explain where this license opens doors, from small passenger vessels to charter, towing and workboat operations within its tonnage and route limits.
Frequently Asked Questions
NM1N here refers to the Master Near Coastal under 100 GRT examination from the USCG National Maritime Center. The original full exam draws on five modules: Q100 (Rules of the Road), Q160 (Deck General), Q161 (Deck Safety), Q162 (Navigation General: Near Coastal) and Q163 (Navigation Problems: Chart Plot).
No. Q165 (Navigation and Deck General/Safety) is a separate module for the OUPV-to-Master Near Coastal under 100 raise-of-grade route. It should not be added to the original five modules.
Stability topics sit inside Q161 Deck Safety, grouped with damage control, vessel construction, trim and stability, man overboard procedures and emergency towing. There is no separate stability module in the original five.
Not necessarily. The full five-module set applies to the original Master Near Coastal under 100 GRT route. Increase-in-scope and raise-of-grade pathways use different published module combinations, so confirm your own route and approval with the NMC. For prerequisites, see NM1N Requirements.
Official percentage weights are not published in the sources used for this guide. Treat the five modules as unweighted preparation groups and study each one. For related reading, see NM1N Pass Rate 2026: What the Data Shows and the broader NM1N Study Guide.