100+ Free USCG Master 500 Practice Questions
Pass your USCG Master Less Than 500 GRT (Oceans/Near Coastal) exam on the first try — instant access, no signup required.
Free surface effect on a vessel with a partially filled tank causes:
Explore More USCG Captain Licenses
Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.
More From This Family
Videos and articles for deeper review.
Key Facts: USCG Master 500 Exam
215
Questions on Oceans Path
USCG ONC03 modules
9
Modules (Q100-Q127)
USCG ONC03 structure
90%
Rules/Plot/Nav-NC Passing
USCG sample exams
80%
Nav Problems Oceans Passing
USCG sample exams
$95
Exam Fee
NMC fee schedule
$240
Typical Original Total Fee
Evaluation + exam + issuance
As of May 13, 2026, the Coast Guard's ONC03 exam path for Master Less Than 500 GRT (Oceans) requires approximately 215 questions across nine modules. Most modules require 70% to pass, but Rules of the Road, Chart Plot, and Navigation Problems Near Coastal require 90%, while Navigation Problems Oceans requires 80%. Major recent process changes are the January 19, 2025 Pay.gov fee shift and the January 28, 2026 NMC ASAP portal rollout. STCW endorsements are typically required for international service on vessels of 500 GT or more.
Sample USCG Master 500 Practice Questions
Try these sample questions to test your USCG Master 500 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1Under COLREGS Rule 19, when two vessels are in or near an area of restricted visibility, every vessel must:
2Under International Rules, a power-driven vessel underway making way through the water shall sound which fog signal?
3A power-driven vessel underway and stopped, not making way through the water, in restricted visibility must sound:
4Under Inland Rules, on the Great Lakes a power-driven vessel of 100 meters or more in length at anchor shall sound, in addition to the rapid bell, what additional sound signal?
5Under Inland Rules, a vessel intending to overtake another in a narrow channel where the overtaken vessel must take action to permit safe passing shall sound:
6A vessel constrained by her draft, when making way under International Rules, may exhibit during the day:
7A vessel engaged in fishing, other than trawling, with outlying gear extending more than 150 meters horizontally from the vessel shall exhibit, in addition to her normal fishing lights:
8Two power-driven vessels are meeting head-on under Inland Rules. The vessel that wants to pass port-to-port should sound:
9Under International Rules, two power-driven vessels are crossing so as to involve risk of collision. The vessel that has the other on her starboard side is the:
10Under both International and Inland Rules, when the stand-on vessel may take action because the give-way vessel is not taking appropriate action, she should:
About the USCG Master 500 Exam
The USCG Master Less Than 500 GRT (ONC03) examination is the knowledge-test path for the Master 500-ton credential used for oceans or near coastal operations on vessels up to 499 gross register tons. Compared to the Master 100 credential, the 500-ton license requires deeper competence in stability calculations, oceans/celestial navigation, and the full breadth of COLREGS and Inland Rules across nine official modules.
Assessment
ONC03 first-issuance oceans path totals approximately 215 questions across nine modules: Q100 Rules of the Road (50, 90% pass), Q120 Deck General I (50, 70%), Q121 Deck General II (50, 70%), Q122 Deck Safety (70, 70%), Q123 Stability Problems (15, 70%), Q124 Navigation General Oceans (70, 70%), Q125 Chart Plot (10, 90%), Q126 Nav Problems Near Coastal (10, 90%), Q127 Nav Problems Oceans (15, 80% — oceans route only).
Time Limit
Up to 3.5 hours per module
Passing Score
70% most modules; 90% Rules of the Road, Chart Plot, Navigation Problems NC; 80% Navigation Problems Oceans
Exam Fee
$95 exam fee; $240 total typical original application (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)
USCG Master 500 Exam Content Outline
Rules of the Road
COLREGS and Inland Rules for restricted visibility, sound signals, narrow channels and TSS, lights and shapes for special-status vessels, steering and sailing scenarios, and danger signals (90% passing required).
Deck General
Seamanship, anchoring/mooring, shiphandling (pivot point, transverse thrust, bow thrusters), USCG forms (CG-719B/K/S/P, CG-2692), Subchapter T/K/H, official logbook entries, and watchkeeping.
Deck Safety
Fire classes and response (PASS, boundary cooling, CO2 systems), SOLAS lifejacket lights, EPIRBs (Cat I/II, 406 MHz), MARPOL Annex V, Williamson/Anderson/Scharnow turns for MOB, hypothermia first aid, heavy weather, and damage control plugging and patching.
Stability Problems
Free surface effect and corrections, KM/KG/GM calculations, fluid GM after FSC, righting arm from cross curves, list versus trim, and Stability Data Reference Book usage (90% passing on related plot modules).
Navigation General Oceans
Compass error (variation and deviation), CDMVT conversions, dip and refraction, LAN latitude, Polaris fixes, intercept method, ECDIS vs ECS, AIS Class A timing, and sea/rain clutter on radar.
Chart Plot
Mercator distance measurement, course-speed-time arithmetic, set-and-drift vectors, three-bearing fixes, and standard chart symbols (90% passing required).
Navigation Problems Near Coastal
Doubling the angle on the bow, distance-to-horizon calculations (1.17 x sqrt(h_ft)), relative-to-true bearing conversion, and ETA arithmetic (90% passing required).
Navigation Problems Oceans
Great circle length (21,600 NM), Mercator vs great circle track shapes, 15-degree time zone changes, and International Date Line crossings (80% passing required, oceans route only).
How to Pass the USCG Master 500 Exam
What You Need to Know
- Passing score: 70% most modules; 90% Rules of the Road, Chart Plot, Navigation Problems NC; 80% Navigation Problems Oceans
- Assessment: ONC03 first-issuance oceans path totals approximately 215 questions across nine modules: Q100 Rules of the Road (50, 90% pass), Q120 Deck General I (50, 70%), Q121 Deck General II (50, 70%), Q122 Deck Safety (70, 70%), Q123 Stability Problems (15, 70%), Q124 Navigation General Oceans (70, 70%), Q125 Chart Plot (10, 90%), Q126 Nav Problems Near Coastal (10, 90%), Q127 Nav Problems Oceans (15, 80% — oceans route only).
- 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 500 Study Tips from Top Performers
Frequently Asked Questions
How many questions are on the USCG Master 500-Ton exam?
The ONC03 first-issuance oceans path totals approximately 215 questions across nine modules: Q100 Rules of the Road (50), Q120 Deck General I (50), Q121 Deck General II (50), Q122 Deck Safety (70), Q123 Stability Problems (15), Q124 Navigation General Oceans (70), Q125 Chart Plot (10), Q126 Navigation Problems Near Coastal (10), and Q127 Navigation Problems Oceans (15, oceans route only). Total modules and questions taken depend on whether you test for the oceans or near-coastal route.
What passing score do I need?
Most modules require 70% to pass. Rules of the Road, Chart Plot, and Navigation Problems Near Coastal require 90%. Navigation Problems Oceans requires 80%. The higher cutoffs reflect the safety-critical nature of collision avoidance and exact plotting.
How long is each exam module?
The Coast Guard sample exams list a maximum time allowed of 3.5 hours per module. Because the exam is modular, total testing time depends on which modules you take and whether you complete them in a single sitting or across multiple sessions at the REC.
How much does the Master 500-Ton exam cost?
The current NMC fee schedule lists a $95 examination fee. For a typical original officer endorsement application the breakdown is $100 evaluation, $95 examination, and $45 issuance, for $240 total. Raise-of-grade applicants from Master 100 GRT have lower evaluation fees.
How does Master 500 differ from Master 100?
Master 500 covers vessels of 100-499 GRT and allows operation on a wider range of vessels and routes (including oceans). The exam is more demanding: nine modules vs five, with dedicated Stability Problems, Navigation General Oceans (with celestial fundamentals), and Navigation Problems Oceans modules. Sea-service requirements are also greater, and STCW endorsements (OICNW, Basic Training, ARPA, ECDIS, GMDSS) typically apply for vessels of 500 GT on international voyages.
What calculator can I bring?
The NMC calculator policy, effective January 1, 2024, accepts the Texas Instruments TI-30XIIS scientific calculator for examinations that require one. Programmable, graphing, or memory-retaining devices are not acceptable for REC testing.
What is the Stability Data Reference Book?
It is the publication candidates use during Q123 Stability Problems and related deck-safety stability questions. The 'white pages' contain free surface corrections and similar reference data; the 'blue pages' contain righting arm tables read by displacement and angle of inclination. Questions test the ability to look up the correct values and apply them to free surface correction, fluid GM, and righting arm problems.