- How the Seven Preparation Groups Map to Real Modules
- Exact Module Sets by Route
- Domain 1: Rules of the Road
- Domains 2 and 3: Deck General and Deck Safety
- Domain 4: Navigation General
- Domain 5: Chart Plot
- Domains 6 and 7: Near Coastal and Oceans Problems
- Scope Extensions Are Not Extra Domains
- Sequencing Your Preparation
- Frequently Asked Questions
- The seven domains are editorial preparation groups covering 17 published module codes, not seven exams every applicant takes.
- TV01 Near Coastal has six modules, TV01 Oceans seven, TV02 Great Lakes and Inland five, TV03 Western Rivers five.
- Q412 and Q413 are alternatives; never count Near Coastal and Oceans Navigation General as simultaneous requirements.
- Western Rivers uses its own Q300, Q423, Q424, Q425 and Q426, so generic Oceans navigation is not a substitute.
How the Seven Preparation Groups Map to Real Modules
The National Master of Towing OC, NC, GL-IN, WR credential is examined through the United States Coast Guard National Maritime Center (NMC). The NMC publishes the examination modules and topic matrices for towing vessel endorsements across three scopes of exam content: TV01, TV02 and TV03. If you are new to the credential itself, start with What Is USCG-MOT? for background.
Here is the point that most generic exam guides get wrong: the "seven domains" in this article are an editorial grouping. They organize all 17 unique published module codes across the four route options into seven preparation groups so you can study logically. They are not a seven-module exam that every towing applicant sits. Depending on your route, you will be assigned five, six or seven modules, and the groups below overlap differently for each route.
The source material is also worth understanding. The published guide referenced here is the regulations-effective March 24, 2014 document (see sections 2.1.5.1 through 2.1.5.3, printed pages 33-34). It is not a newly issued 2026 blueprint, though current indexed NMC matrices corroborate the module headings used below. One small quirk: the TV03 page's endorsement subheading says Apprentice Mate, but the same page's matrix title, the overall towing index and the published guide all cover Master, Mate and Apprentice Mate. Treat TV03 as covering all three.
Exact Module Sets by Route
This table is the backbone of everything that follows. Find your route, then read only the domain sections that apply to you.
| Route | Scope | Modules | Count |
|---|---|---|---|
| Near Coastal | TV01 | Q100, Q410, Q411, Q412, Q414, Q415 | 6 |
| Oceans | TV01 | Q100, Q410, Q411, Q413, Q414, Q415, Q416 | 7 |
| Great Lakes and Inland | TV02 | Q100, Q418, Q419, Q420, Q421 | 5 |
| Western Rivers | TV03 | Q300, Q423, Q424, Q425, Q426 | 5 |
Notice what the table reveals. Q412 and Q413 are alternatives to each other, and Q416 appears only on the Oceans route. The two TV01 routes share most of their modules, while TV02 and TV03 each run a five-module set. The Western Rivers set shares no module code with the others except by function: it swaps in its own Inland rules module and its own deck, safety, navigation and chart plot modules.
Domain 1: Rules of the Road
Rules of the Road: Inland and International (Q100) or Inland (Q300)
Q100 covers both Inland and International rules for TV01 and TV02 candidates. Western Rivers candidates in TV03 take Q300, which covers Inland rules.
- Know which rule set governs your route; Q100 includes both, Q300 only Inland
- Expect to apply rules to vessel situations, not just recall rule numbers
- Towing-specific situations (tows, restricted maneuverability, lights and shapes for tows) deserve extra attention
This is the one domain every non-Western-Rivers route shares in the same form, which makes it a sensible first block of study. For Western Rivers candidates, the distinction matters: Q300 is an Inland-focused module, so international rule content is not what you are being tested on under that route. For a look at how demanding the overall credential feels, see How Hard Is the USCG-MOT Exam?
Domains 2 and 3: Deck General and Deck Safety
These two groups cover the day-to-day operating knowledge of a towing vessel. The module codes differ by route, but the preparation logic is parallel.
| Preparation Group | OC / NC | Great Lakes and Inland | Western Rivers |
|---|---|---|---|
| Deck General | Q410 | Q418 | Q423 |
| Deck Safety | Q411 | Q419 | Q424 |
Deck General (Q410, Q418, Q423)
This group is where towing operations live. On the Western Rivers route, Q423 specifically covers barge operations and hazardous cargo, which reflects the realities of river tows pushing multiple barges.
- Towing operations and the handling of tows
- Barge operations, especially for Western Rivers candidates
- Hazardous cargo knowledge where your module covers it
Deck Safety (Q411, Q419, Q424)
For Western Rivers candidates, Q424 covers stability, construction and damage control. Treat that heading as a useful indicator of the kind of thinking this group demands across routes: how a vessel behaves, how it is built, and how you respond when something goes wrong.
- Stability concepts as they apply to towing vessels and tows
- Vessel construction fundamentals
- Damage control and emergency response
Domain 4: Navigation General
Navigation General: Q412 or Q413; Q420; Q425
This is the group where alternatives matter most. For TV01 Near Coastal, the module is Q412. For TV01 Oceans, it is Q413. These are alternatives, never simultaneous requirements. TV02 uses Q420 for Great Lakes and Inland, and TV03 uses Q425 for Western Rivers navigation.
- Near Coastal and Oceans candidates take one of Q412 or Q413, not both
- Great Lakes and Inland candidates study the Q420 content for their waters
- Western Rivers candidates must study river-specific navigation (Q425), not Oceans navigation
A common planning mistake is to see Q412 and Q413 both listed in a single preparation group and assume the exam includes both. It does not. Only one applies to any given full-route applicant. If you are weighing which route to pursue, USCG-MOT Requirements 2026: Eligibility, Prerequisites & How to Qualify walks through the qualification side.
Domain 5: Chart Plot
Navigation Problems: Chart Plot (Q414, Q421, Q426)
Q414 serves the OC/NC routes, Q421 serves Great Lakes and Inland, and Q426 serves Western Rivers. Chart plotting is hands-on problem solving rather than recall: you work with chart information to solve navigation problems.
- Practice working problems end to end, not just reading about techniques
- Learn the instruments and tools you are permitted to use at the testing site
- Accuracy under time pressure is the skill being measured
Chart plot modules reward repetition more than almost any other group because the skill is procedural. Candidates who treat it as memorization tend to struggle. Our USCG-MOT Study Guide 2026 covers how to build that kind of procedural fluency, and the main practice test site is a good place to drill the knowledge-based modules while you work plots by hand.
Domains 6 and 7: Near Coastal and Oceans Problems
These last two groups apply only to TV01 candidates, which makes them the easiest to rule in or out of your plan.
Domain 6: Navigation Problems: Near Coastal (Q415)
Q415 appears on both TV01 routes, Near Coastal and Oceans. If you are on TV01, plan for it. If you are on TV02 or TV03, it does not apply to a full-route exam.
Domain 7: Navigation Problems: Oceans (Q416)
Q416 is Oceans-only. It is the single module that separates the seven-module Oceans route from the six-module Near Coastal route, aside from the Q412 versus Q413 swap. Candidates pursuing Near Coastal can skip it entirely.
| Group | Near Coastal | Oceans | Great Lakes and Inland | Western Rivers |
|---|---|---|---|---|
| Domain 6 (Q415) | Yes | Yes | No | No |
| Domain 7 (Q416) | No | Yes | No | No |
Scope Extensions Are Not Extra Domains
If you already hold an endorsement and are adding scope, the NMC publishes separate extension module sets. These are separate from the full-route sets and must never be added into the full-route domain count.
| Extension | Modules |
|---|---|
| Near Coastal to Oceans | Q413 + Q416 |
| GL/Inland to Near Coastal | Q412 + Q415 |
| GL/Inland to Oceans | Q413 + Q415 + Q416 |
| Western Rivers to GL/Inland | Q100 + Q420 + Q421 |
| Adding Western Rivers to OC/NC/GL-IN | Q425 + Q426 |
| Western Rivers to OC/NC | Full exam required |
Sequencing Your Preparation
Once you know your route, order matters more than volume. Here is one sensible sequence for a TV01 Oceans candidate, the largest module set; trim it to fit your own assignment.
Rules of the Road (Q100)
- Foundational and shared across TV01 and TV02, so it pays off early
- Pair with lights and shapes practice
Deck General and Deck Safety (Q410, Q411)
- Knowledge-heavy modules suited to question-based drilling
Navigation General (Q413) and Chart Plot (Q414)
- Concepts first, then procedural plotting practice
Navigation Problems (Q415, Q416)
- Saved for last because they build on every earlier navigation skill
Western Rivers candidates would substitute the Q300, Q423, Q424, Q425 and Q426 sequence in the same order. For a condensed refresher once you are close to exam day, the USCG-MOT Cheat Sheet 2026 is a handy companion.
Frequently Asked Questions
No. The seven domains are editorial preparation groups. Full-route candidates take five, six or seven assigned modules depending on route, and extension candidates take even fewer. Your NMC approval to test lists your exact modules.
No. They are alternatives. Near Coastal uses Q412 and Oceans uses Q413. They should never be counted together as simultaneous requirements.
Not safely. Western Rivers has its own modules: Q300 for Inland rules, Q423 for barge operations and hazardous cargo, Q424 for stability, construction and damage control, Q425 for navigation, and Q426 for chart plot.
The NMC publishes modules and topic matrices, but the sources reviewed here do not establish domain percentages, a single overall question count or duration, or current fees. Check the NMC directly and see USCG-MOT Certification Cost 2026 and USCG-MOT Passing Score 2026 for related coverage.
No. The published guide referenced is the regulations-effective March 24, 2014 document, with current indexed NMC matrices corroborating the module headings. Always confirm against the current NMC pages for your route.