0.4 ONC06 Exam Format, Modules, Scoring & REC Logistics

ONC06 at a Glance

ONC06 is the National Maritime Center exam code for original Master Less Than 100 GRT Near Coastal. Unlike a single continuous standardized test, Coast Guard deck officer exams are modular. You must pass each module at its own cut score. Failing Chart Plot does not erase a passed Rules module, but you are not finished until every required module for your transaction is passed (or properly substituted by an approved course).

Original ONC06 is built from five modules totaling 210 questions:

Memorize the 90% modules: Rules (Q100) and Chart Plot (Q163). Those two fail more career plans than any 70% module because the margin for error is tiny — five wrong on Rules or two wrong on Chart Plot and you retake that module.

Raise of Grade: OUPV NC → Master NC

If you already hold OUPV Near Coastal and are raising grade to Master Near Coastal LT 100, you typically do not repeat the entire ONC06 battery. The raise-of-grade exam is module Q165 — Navigation/Deck General/Safety combined style content — 50 questions at 70%. You still must meet Master sea service and tonnage rules and pay evaluation/issuance fees, but the exam burden is one 50-question module instead of 210 questions.

Confirm your approval letter lists Q165 (or the exact modules NMC assigned). Do not walk into an REC assuming raise-of-grade content if your letter still lists full original modules.

Time Limits and REC Administration

Modules are administered at a Regional Exam Center (REC) or other Coast Guard-authorized exam site. Plan for up to 3.5 hours per module. That is generous for a well-prepared candidate on Deck General, but Chart Plot can feel tight if your plotting workflow is messy, and Rules can feel long if you second-guess every light configuration.

REC logistics you should expect

• Appointment-based testing; bring the approval/exam authorization documents NMC or the REC requires
• Government photo ID matching your MMC application name
• No phones, smartwatches, notes, or unauthorized references in the exam room
• Coast Guard-provided or approved plotting tools / chart materials as specified for Q163
• Module results recorded toward your credential file; failed modules are retaken after any waiting rules the REC applies

Arrive early, know parking and ID rules, and treat the REC like a professional board appearance — you are testing for the right to command paying passengers.

Calculator Policy (TI-30XIIS, Effective January 1, 2024)

Effective January 1, 2024, Coast Guard deck exam calculator policy centers on the Texas Instruments TI-30XIIS (and any updated list of explicitly approved models NMC publishes). Personal graphing calculators, phone calculators, and unapproved scientific models are not allowed. Practical preparation advice:

• Buy a TI-30XIIS early and use only that model for all navigation math practice.
• Learn its fraction, degree, and memory keys before exam day so you do not waste Q162/Q163 time fighting the interface.
• Confirm with your REC the week you test in case the approved list is amended; never assume a "similar" calculator is fine.

Navigation General and Chart Plot reward candidates who already think in 60 miles per degree of latitude, speed-time-distance, and set and drift on the same calculator they will hold under the proctor's eye.

Approved Course Substitution

An NMC-approved course for Master LT 100 (or specific modules) can substitute for exam modules when completed successfully under the school's approval. That path trades exam anxiety for tuition and attendance. If you go the school route:

• Verify the school and course are currently approved for the modules you need
• Complete every attendance and assessment requirement; incomplete courses do not substitute
• Still master the material — the credential is useless if you cannot run COLREGS and a chart plot on the water

Many mariners mix paths: school for Chart Plot and Navigation, self-study for Rules, or the reverse. Either way, this study guide's later chapters map directly to Q100, Q160, Q161, Q162, and Q163 content.

Scoring Math You Must Internalize

There is no "average across modules." A 100% on Deck Safety does not rescue a 88% on Rules. Pass/fail is per module.

Study Strategy: Front-Load Rules (90%)

Because Q100 requires 90%, the highest-ROI study order for most original candidates is:

1. Rules of the Road (Q100) — COLREGS and Inland Rules, lights, shapes, sound signals, restricted visibility, responsibilities between vessels. Drill until missing fewer than five on full 50-question sets is normal, not lucky.
2. Chart Plot (Q163) — only 10 questions but 90%. Build a repeatable plot routine: setup, DR, fix, set/drift, course to steer, labeling. One sloppy plot fails the module.
3. Navigation General NC (Q162) — tides, currents, compass error, ATON, publications, weather, piloting theory that supports the plot.
4. Deck Safety (Q161) — fire, abandon ship, MOB, survival, passenger safety, emergencies on small passenger vessels.
5. Deck General (Q160) — seamanship, anchors, marlinespike, shiphandling, documents, basic maritime law as tested.

Weekly rhythm (example 10–12 week plan)

• Weeks 1–4: Rules daily (lights/shapes/sound heavy); start light Nav Gen.
• Weeks 5–7: Chart Plot labs + Nav Gen; maintain Rules review three times weekly.
• Weeks 8–9: Deck Safety and Deck General content blocks.
• Weeks 10–12: Full mixed practice; timed modules; weak-topic repair; Rules and Plot never drop below passing in practice.

Exam-day tactics

• On Rules, trust first trained recognition of lights and situations; change answers only when you find a clear rule conflict.
• On 70% modules, flag hard items and keep moving; fifteen wrong is a wide cushion if you do not blank twenty easy ones by mismanaging time.
• On Chart Plot, neatness is accuracy. Misread a distance scale or reverse set/drift and a single error can cost the module.
• Sleep and logistics matter: a missed REC appointment burns weeks.

How This Guide Maps to ONC06

Subsequent chapters walk Rules rule-by-rule, then Deck General seamanship and shiphandling, Deck Safety emergencies and stability/safety topics as tested, Navigation General Near Coastal, and Chart Plot technique. Use module codes Q100 / Q160 / Q161 / Q162 / Q163 as your mental filing system. When a practice question feels "Deck Safety-ish," file it under Q161; when it is pure COLREGS, it is Q100 at the 90% standard.

Final orientation before Chapter 1 content

You now know what Master LT 100 is, who qualifies under 46 CFR 11.428 and 11.422, how the MMC package and Pay.gov / ASAP process works, and how ONC06 is scored. The remaining work is professional knowledge: the same knowledge that keeps passengers safe on a foggy whale-watch departure and keeps your COI vessel inside its route and manning box. Start Rules early, protect the 90% modules, and treat every study hour as time on watch.