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Question 1

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Under Rule 5, a proper lookout must be maintained by:

Radar alone if visibility is reduced

Sight and hearing as well as by all available means appropriate to the circumstances

The vessel operator only, without help from crew

Listening to VHF traffic unless the vessel is in a harbor

to track

2026 Statistics

Key Facts: USCG Master 100 Exam

210

Questions on Original Path

USCG ONC06 sample exams

90%

Rules/Plot Passing Score

USCG sample exams

3.5 hrs

Max Time per Module

USCG sample exams

$95

Exam Fee

NMC fee schedule

$240

Typical Original Total Fee

Evaluation + exam + issuance

Jan 28, 2026

ASAP Portal Rollout

NMC ASAP notice

As of March 12, 2026, the Coast Guard's ONC06 sample-exam structure for Master Less Than 100 GRT Near Coastal/Inland still uses five modules totaling 210 questions: four 50-question modules plus a 10-question chart-plot module. Most modules require 70% to pass, but Rules of the Road and Chart Plot require 90%. I did not find a separate 2026 blueprint change to those module weights; the main recent applicant-facing changes are the January 19, 2025 Pay.gov fee-payment shift and the January 28, 2026 ASAP application-portal rollout.

Sample USCG Master 100 Practice Questions

Try these sample questions to test your USCG Master 100 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 200+ question experience with AI tutoring.

1Under Rule 5, a proper lookout must be maintained by:

A.Radar alone if visibility is reduced

B.Sight and hearing as well as by all available means appropriate to the circumstances

C.The vessel operator only, without help from crew

D.Listening to VHF traffic unless the vessel is in a harbor

Explanation: Rule 5 requires every vessel to keep a proper lookout by sight and hearing and by all available means appropriate to the situation. That includes human observation, radar, AIS, radio information, and any other tools that help assess traffic and collision risk.

2You observe another vessel by compass bearing, and its bearing remains nearly constant while the range is closing. What should you assume?

A.There is no risk because the bearing is not changing

B.The other vessel must be overtaking you

C.Risk of collision exists

D.Only the other vessel has collision responsibility

Explanation: A steady or nearly steady bearing with decreasing range is one of the classic indicators of collision risk under Rule 7. The safe assumption is that risk of collision exists and must be evaluated promptly.

3Which factor is specifically listed in Rule 6 as an additional safe-speed consideration for vessels using radar?

A.The age of the vessel's hull

B.The amount of fuel remaining aboard

C.Limitations imposed by the radar range scale in use

D.The seniority of the watchstander

Explanation: Rule 6 adds radar-specific factors when operational radar is available, including limitations of the equipment and the range scale being used. A radar picture can mislead the operator if scale, sea clutter, rain clutter, or small-target detection limits are ignored.

4A very large ship shows an appreciable change of bearing, but the vessels are already close. Under Rule 7, what is the safest conclusion?

A.An appreciable bearing change always means there is no collision risk

B.Risk exists only if both vessels are power-driven

C.The give-way vessel may wait until the last minute to maneuver

D.Risk of collision may still exist despite the bearing change

Explanation: Rule 7 warns that collision risk can still exist even with an appreciable bearing change, especially when approaching a very large vessel, a tow, or a target at close range. Large targets can close dangerously before the bearing change becomes meaningful in practice.

5When action is taken to avoid collision, Rule 8 says it should be:

A.Positive, made in ample time, and large enough to be readily apparent

B.Delayed until the other vessel sounds a danger signal

C.A series of very small course changes to avoid alarming traffic

D.Limited to speed changes only

Explanation: Rule 8 requires action to avoid collision to be positive, timely, and substantial enough to be obvious to the other vessel. Tiny or hesitant maneuvers can confuse the situation and fail to resolve the close-quarters risk.

6In restricted visibility, you detect by radar alone another vessel forward of your beam. Which action does Rule 19 generally say to avoid?

A.An alteration to port for a vessel forward of the beam

B.Reducing speed to bare steerageway if needed

C.Taking early action based on radar information

D.Listening for fog signals

Explanation: Rule 19 advises a vessel that detects another by radar alone to avoid, so far as possible, altering course to port for a vessel forward of the beam, except when overtaking. The rule is intended to reduce the chance of turning across another vessel's track in fog or other restricted visibility.

7If there is any doubt whether risk of collision exists, the Rules require you to:

A.Assume there is no risk until a whistle signal is heard

B.Assume risk of collision does exist

C.Stand on and maintain speed until the CPA reaches zero

D.Wait for VTS or the Coast Guard to give instructions

Explanation: The Rules state that if there is any doubt, risk of collision shall be deemed to exist. That standard is deliberately conservative and is meant to force early, prudent decision-making.

8Which watch arrangement best satisfies proper-lookout requirements on a busy night transit?

A.Leaving the helm unattended while the autopilot steers

B.Using only AIS because it identifies nearby traffic

C.Assigning a lookout and using sight, hearing, radar, and other available means together

D.Relying on the chartplotter because all vessels are shown on electronic charts

Explanation: A proper lookout is a combined human-and-equipment task, especially at night or in traffic. Radar and AIS can help, but they do not replace visual observation, listening, and active bridge watchkeeping.

9Why are a succession of small course changes usually poor collision-avoidance practice?

A.They are required only for vessels over 100 gross tons

B.They may not be readily apparent to the other vessel

C.They are prohibited in daylight

D.They automatically transfer fault to the stand-on vessel

Explanation: Rule 8 expects a maneuver to be large enough to be readily apparent to another vessel observing you visually or by radar. Multiple small changes can be misread, delay the resolution, and leave both vessels uncertain about the situation.

10Safe speed is the speed at which a vessel can:

A.Always stay on plane in rough water

B.Stop within one vessel length in all conditions

C.Maintain maximum steerage regardless of visibility

D.Take proper and effective action to avoid collision and be stopped within an appropriate distance

Explanation: Rule 6 defines safe speed in practical terms: the vessel must be able to avoid collision effectively and stop within a distance suitable for the existing conditions. Safe speed changes with visibility, traffic density, draft, sea state, and maneuvering characteristics.

About the USCG Master 100 Exam

The USCG Master 100-Ton Captain License exam is the knowledge-test path for Master Less Than 100 GRT credentials used for near coastal or inland passenger-vessel operations. The official sample-exam structure emphasizes Rules of the Road, deck seamanship and safety, navigation fundamentals, and chart-plotting competence.

Assessment

Original ONC06 path: Rules of the Road (50), Deck General (50), Deck Safety (50), Navigation General (50), and Chart Plot (10). Raise of grade from OUPV Near Coastal uses module Q165 (50 questions).

Time Limit

Up to 3.5 hours per module

Passing Score

70% most modules; 90% Rules of the Road and Chart Plot

Exam Fee

$95 exam fee; $240 total typical original application (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

USCG Master 100 Exam Content Outline

23.8% official weight

Rules of the Road

Lookout responsibilities, risk of collision, steering and sailing rules, lights and shapes, sound signals, narrow channels, and traffic separation schemes.

23.8% official weight

Deck General

Seamanship, line handling, anchoring, stability and tonnage basics, vessel documents, passenger operations, and watchkeeping responsibilities.

23.8% official weight

Deck Safety

Required safety equipment, firefighting, survival craft, emergency procedures, first aid, pollution prevention, heavy-weather decisions, and damage control.

23.8% official weight

Navigation General

Charts and publications, aids to navigation, compass error, bearings, tides and currents, piloting, dead reckoning, and marine weather interpretation.

4.8% official weight

Chart Plot

Course, speed, time, distance, set and drift, fixes, and chart-work reasoning using standard plotting methods.

How to Pass the USCG Master 100 Exam

What You Need to Know

Passing score: 70% most modules; 90% Rules of the Road and Chart Plot
Assessment: Original ONC06 path: Rules of the Road (50), Deck General (50), Deck Safety (50), Navigation General (50), and Chart Plot (10). Raise of grade from OUPV Near Coastal uses module Q165 (50 questions).
Time limit: Up to 3.5 hours per module
Exam fee: $95 exam fee; $240 total typical original application

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

USCG Master 100 Study Tips from Top Performers

1Overprepare for Rules of the Road because it carries both a full 50-question module and a 90% passing requirement.

2Memorize the practical differences among meeting, crossing, and overtaking situations instead of relying on vague right-of-way intuition.

3Drill lights, day shapes, and sound signals until you can recognize the vessel situation immediately from a short fact pattern.

4Practice deck questions in scenario form: anchoring choices, passenger counts, stability implications, required documents, and casualty response.

5Study navigation fundamentals with pencil-and-paper distance, speed, time, set, drift, and course-to-steer problems, even when the question is text only.

6Use tide and current questions to reinforce both terminology and practical effect on ETA, course, and safe bridge transit decisions.

7Build a short emergency-action checklist for fire, flooding, man overboard, grounding, and heavy weather so you answer safety questions consistently.

8Take timed sets of 50 questions to match the Coast Guard module rhythm and to learn when to move on from a difficult problem.

Frequently Asked Questions

How many questions are on the USCG Master 100-Ton exam?

For the original ONC06 path, the Coast Guard sample-exam guide shows 210 total questions: Rules of the Road (50), Deck General (50), Deck Safety (50), Navigation General (50), and Chart Plot (10). If you are raising grade from OUPV Near Coastal to Master Less Than 100 GRT Near Coastal, the guide lists a separate 50-question Q165 module instead.

What passing score do I need?

Most modules require 70% to pass. Rules of the Road and the Chart Plot module are stricter and require 90%, which means you need especially strong mastery of collision-avoidance rules and basic chart-work accuracy.

How long is the exam?

The current Coast Guard sample exams list a maximum time allowed of 3.5 hours per module. Because the original exam path is modular, your total testing time depends on which modules you take and whether you test them together or across separate sessions.

How much does the Master 100-Ton exam cost?

The current NMC fee schedule lists a $95 examination fee. For a typical original officer endorsement application, the current breakdown is $100 evaluation, $95 examination, and $45 issuance, for $240 total; raise-of-grade applications are lower on the evaluation portion.

What changed for 2026 applicants?

I did not find a separate 2026 change to the ONC06 exam-module structure itself. The main current process changes are that fee payments shifted to Pay.gov on January 19, 2025, and the new NMC ASAP portal launched on January 28, 2026 as the current online application route.

What calculator can I bring?

The NMC calculator policy page states that, effective January 1, 2024, the Texas Instruments TI-30XIIS is the accepted scientific calculator model for examinations that require one. Programmable, graphing, or memory-retaining devices are not acceptable for REC testing.

What topics matter most for scoring?

Rules of the Road is high stakes because it is both a full 50-question module and a 90% passing requirement. After that, the largest study blocks are Deck General, Deck Safety, and Navigation General, each carrying 50 questions in the official sample-exam structure.