- NM1N here means National Master 100 NC: a Master Near Coastal license for vessels under 100 gross register tons.
- The United States Coast Guard National Maritime Center administers the examination, not a private certifying body.
- The full exam draws on five modules: Q100, Q160, Q161, Q162, and Q163.
- Q165 is a separate raise-of-grade module and is not part of the original five.
What the Acronym Means Here
If you searched "what does NM1N mean" and landed on a page about nautical charts and collision regulations, you are in the right place. On this site, NM1N stands for National Master 100 NC. Read it as a plain-language label for a mariner credential: a Master license, valid for Near Coastal (NC) waters, on vessels of less than 100 gross register tons.
The acronym is shorthand used by this study site. Official Coast Guard materials do not hand you a card that says "NM1N." They describe the credential as the Master Near Coastal less-than-100-GRT license and organize its examination into numbered modules. The label simply gives candidates one compact name to search for and study around.
Because several unrelated credentials in other industries happen to share similar-looking letter strings, it is worth being precise: nothing on this page concerns IT, healthcare, or any non-maritime certification. Everything below is about a U.S. merchant mariner license examined on seamanship, navigation, safety, and the rules of the road. For alternate phrasings of the same question, see our explainers on what NM1N stands for and the NM1N meaning, or the broader overview at What Is NM1N?
Who Stands Behind It
The governing body is the United States Coast Guard National Maritime Center (NMC). The NMC evaluates mariner applications, approves candidates to test, and publishes the examination guides and module topic indexes that define what can appear on the exam. There is no third-party testing company whose syllabus you must buy; the NMC's published materials are the source of truth.
One practical consequence: official percentage weights per topic are not published in the materials we rely on. Any site claiming "Q160 is exactly 30% of your grade" is guessing. We organize preparation into unweighted, route-aware study groups instead, and we say so plainly.
The Five Modules Behind the Name
The original Master Near Coastal less-than-100-GRT full examination uses five modules, identified by Coast Guard question-bank codes: Q100, Q160, Q161, Q162, and Q163. These map directly to the five exam domains candidates prepare for. For a deeper walk-through of each, see our complete guide to all five content areas.
Domain 1: Rules of the Road: International and Inland (Q100)
The navigation rules module covering both the international and inland regimes. Expect to move fluidly between them.
- Watchkeeping
- COLREGS (international rules)
- Inland Navigational Rules
Domain 2: Deck General (Q160)
The broadest module, spanning seamanship, emergencies, handling, and shipboard business.
- Seamanship, marlinspike seamanship, purchases, blocks and tackle
- Vessel maneuvering and handling, including turn circle, pivot point, advance and transfer, and wake reduction
- Collision, fire or explosion, abandon ship procedures, rescuing survivors from a ship or aircraft in distress
- Fire prevention and firefighting appliances, classes and chemistry of fire, basic firefighting
- Lifesaving, lifesaving appliance operation, survival at sea, emergency procedures
- Communications and radiotelephone; signals (storm, wreck, distress, special)
- Certificates and documents required; ship's business; vessel power plants; small engine operations and maintenance; temporary repairs
Domain 3: Deck Safety (Q161)
Stability, construction, and damage control, plus emergency response topics.
- Trim and stability; principles of vessel construction
- Passenger and crew safety in emergencies
- Man overboard procedures and emergency towing
- Fire or explosion; fire prevention and firefighting appliances
- Abandon ship procedures; rescuing survivors from a ship or aircraft in distress
- Vessel power plants; small engine operations and maintenance
Domain 4: Navigation General: Near Coastal (Q162)
The theory side of navigation: compasses, charts, publications, weather, and tides.
- Piloting, distance off, bearing problems, fix or running fix, dead reckoning
- Aids to navigation; charts, navigation publications, and Notices to Mariners
- Magnetic and gyro compass principles; magnetic compass error and correction; determination of compass error
- Terrestrial observation and instruments and accessories
- Meteorology and oceanography: weather systems, ocean current systems, weather charts and reports, tides and tidal currents
Domain 5: Navigation Problems: Chart Plot (Q163)
The applied side: you work problems on a chart rather than recall definitions.
- Piloting, distance off, bearing problems, fix or running fix
- Chart navigation and dead reckoning
- Electronic navigation
- Instruments and accessories; aids to navigation; charts, publications, and Notices to Mariners
What the Questions Feel Like
Two very different skills are being tested, and conflating them is the most common planning error.
Recall-and-judgment modules
Q100, Q160, Q161, and the theory-heavy Q162 reward knowing the right rule, procedure, or definition and applying it to a situation. Rules of the Road questions in particular ask you to identify lights, shapes, signals, and the correct action, and the international-versus-inland distinction means a fact that is right under one regime can be wrong under the other. Learning the two sets side by side, rather than sequentially, pays off.
Chart-work module
Q163 is the odd one out. It is about plotting: setting up a fix or running fix, working dead reckoning, solving distance-off and bearing problems, and using the chart and publications correctly. Memorization alone will not carry you here; fluency with dividers, parallel rulers, and the chart conventions will. If you are weak on chart plotting, the content is learnable, but it needs hands-on repetition rather than reading.
Key Takeaway
Treat Q163 as a skill you practice with a real chart or realistic plotting exercises, and treat Q100, Q160, Q161, and most of Q162 as knowledge you drill with questions. Different modules need different kinds of practice.
For a candid look at where candidates struggle, see How Hard Is the NM1N Exam? and, for scoring mechanics, NM1N Passing Score.
Different Routes, Different Module Sets
"NM1N" describes a destination, but the Coast Guard recognizes more than one road to it, and the modules you actually sit depend on which road you are on. Our facts support the following distinctions, and it is important not to add them together.
| Route | Modules | Notes |
|---|---|---|
| Original Master Near Coastal, less than 100 GRT (full exam) | Q100, Q160, Q161, Q162, Q163 | The five-domain structure this site is organized around. |
| OUPV-to-Master Near Coastal under 100 GRT (raise of grade) | Q165 (Navigation and Deck General/Safety) | A separate module; not one of the original five. |
| Increase in scope: Great Lakes/Inland to Near Coastal | Q160 + Q162, plus Q100 where a COLREGS limitation applies | Based on the published guide; do not combine with other routes. |
The mistake to avoid is treating these as additive. A candidate on the increase-in-scope path does not "owe" all five modules plus Q165. Equally, someone preparing for the full original exam should not assume Q165 is hiding inside it. These are distinct pathways, and the right one is determined by your credential history and the Coast Guard's evaluation of your application. Our requirements breakdown covers eligibility in more depth.
Approval, Fees, and Timers: What Not to Assume
Many candidates want a single number for exam cost and a single clock for how long they get. Here we are deliberately conservative, because the published facts do not support universal figures.
- Approval comes first. You test on the strength of an individual approval to test issued through the Coast Guard process, not by simply walking in.
- Fees are not universal. We do not quote a flat exam fee here because credential, route, and application circumstances affect what you pay. Check current NMC fee information for your specific application.
- Timers and module groupings vary. Do not assume one fixed time limit applies to every candidate and every module combination.
- Dates are set by your approval and the testing location, not by a single national calendar.
Who Actually Uses This Credential
A Master Near Coastal license under 100 GRT is a working mariner's credential. It is held by the people who run smaller commercial vessels operating beyond the sheltered inland waters, out to the near-coastal limit. In practice that tends to mean captains and operators associated with:
- Charter and passenger boats running inspected or uninspected service
- Fishing and other commercial small-vessel operations
- Towing, workboat, and support-vessel work
- Ferry, tour, and sightseeing operations
- Dive support, research, and pilot-type small craft
Employers in these fields care about whether the license on your wall matches the vessel size and route they operate. The credential itself, not a job title, is what lets you serve as master. We do not put salary figures on this page because the published facts for this credential do not include them; if you want a qualitative discussion of earnings and demand, see the NM1N Salary Guide, the broader NM1N jobs overview, and the cost-versus-benefit framing in Is the NM1N Certification Worth It?
Reading the Credential Like a Hiring Manager
When an operator reads "Master Near Coastal under 100 GRT," three questions run through their head: can you legally take this boat to this distance from shore, do you understand the rules well enough to avoid collisions, and can you handle an emergency with a small crew. The five modules are essentially those three questions in exam form.
- Distance and route legality is the near-coastal navigation question (Q162, Q163).
- Collision avoidance is the rules question (Q100).
- Emergency competence is the safety and general-deck question (Q160, Q161).
Seen this way, the exam is less a trivia contest than a structured verification that you can be trusted with a vessel and the people aboard it.
Sequencing the Modules
This is the one place we will talk about study scheduling, and only because the module structure suggests an order. Chart plotting depends on rules and navigation theory, so it makes sense to build in that direction rather than treating five modules as five equal, independent piles.
Q100: Rules of the Road
- Learn International and Inland side by side
- Drill lights, shapes, signals, and watchkeeping duties
Q162: Navigation General
- Compass error and correction, aids to navigation, publications
- Weather, ocean currents, tides and tidal currents
Q163: Chart Plot
- Daily plotting: fixes, running fixes, dead reckoning, distance off
- Practice with real chart tools until it is automatic
Q160 and Q161: Deck General and Safety
- Emergencies, firefighting, lifesaving, and handling
- Trim and stability, construction, damage control
Why this order? Rules and navigation theory feed directly into the plotting problems, and Q160/Q161 cover a wide spread of procedures that benefit from being reviewed last, closest to test day. Adjust to your own weak spots; a former commercial fisherman may breeze through seamanship and need extra time on Q162. For a fuller plan, our NM1N study guide and the condensed NM1N cheat sheet are good companions, and you can pressure-test yourself with questions on the main practice test site.
Key Takeaway
Organize by dependency, not by page count: rules and theory first, then chart work, then the broad safety and general-deck material. Use practice questions to find which module is actually dragging your score.
Frequently Asked Questions
On this site, NM1N means National Master 100 NC: a Master Near Coastal license for vessels under 100 gross register tons, examined by the United States Coast Guard National Maritime Center. For more variants of the question, see What Does NM1N Mean? and What Is NM1N Certification?
The original Master Near Coastal under-100-GRT full examination uses Q100 (Rules of the Road), Q160 (Deck General), Q161 (Deck Safety), Q162 (Navigation General: Near Coastal), and Q163 (Navigation Problems: Chart Plot).
Not part of the original five. Q165, Navigation and Deck General/Safety, is a separate module used for the OUPV-to-Master Near Coastal under 100 GRT raise of grade, so do not add it to the full-exam list.
No official percentage weights are published in the materials this guide relies on. Treat the five domains as unweighted preparation groups and verify details against the NMC's current module-topic index and your individual approval to test.
It depends on your route. The full original exam uses all five, while an increase in scope from Great Lakes/Inland to Near Coastal uses Q160 and Q162, plus Q100 where a COLREGS limitation applies. Routes are not added together, and your approval determines what you sit. See the pass rate discussion for what we can and cannot say about outcomes.