All Practice Exams

100+ Free USCG Master OSV Practice Questions

Prepare for the USCG Master / Chief Mate of Offshore Supply Vessels (Oceans or Near Coastal) exam with instant access — no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
Not publicly disclosed Pass Rate
100+ Questions
100% Free

Loading practice questions...

2026 Statistics

Key Facts: USCG Master OSV Exam

OSV01

NMC Exam Code

USCG National Maritime Center

~375 catalog items

OSV01 Module Listing Total

USCG NMC OSV01 modules

90%

Rules of the Road Pass Mark

USCG NMC Q100

70%

Most Module Pass Mark

USCG NMC OSV01

$255

Typical Original Upper-Level Total

46 CFR 10.219 ($100+$110+$45)

5 years

Credential Validity

USCG Merchant Mariner Credential

Pay.gov

Fee Payment Method (since 2025-01-19)

USCG NMC fees page

The USCG Master/Chief Mate OSV exam (NMC OSV01) is the upper-level deck license battery for offshore supply vessel officers. Official modules include Q100 Rules of the Road (50 questions, 90% pass), Q200 Deck General (70, 70%), Q201 Deck Safety (70, 70%), Q202 Stability Problems (10, 70%), Navigation General Near Coastal or Oceans (Q203/Q204, 70, 70%), Q205 Chart Plot (10, 90%), Q206 Nav Problems Near Coastal (10, 90%), and Q207 Nav Problems Oceans (15, 80%). Catalog modules sum to about 375 items; actual modules depend on Oceans vs Near Coastal route. Typical original upper-level MMC fees are $100 evaluation + $110 examination + $45 issuance (~$255) under 46 CFR 10.219, paid via Pay.gov since 19 January 2025. Raise of grade from Chief Mate OSV to Master OSV is generally without further professional examination once service requirements are met.

Sample USCG Master OSV Practice Questions

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

1Under the International Rules (COLREGS), a power-driven vessel underway and not engaged in special operations exhibits which lights at night?
A.Sidelights and a sternlight only
B.An all-round white light and sidelights only
C.Masthead light(s), sidelights, and a sternlight
D.Two all-round red lights in a vertical line
Explanation: Rule 23 requires a power-driven vessel underway to show masthead light(s), sidelights, and a sternlight. Vessels 50 m or more in length show a second after masthead light higher than the forward one.
2In a crossing situation under the International Rules, when two power-driven vessels are crossing so as to involve risk of collision, which vessel must keep out of the way?
A.The vessel which has the other on her own port side
B.The vessel which has the other on her own starboard side
C.The faster vessel
D.The larger vessel
Explanation: Rule 15 states that when two power-driven vessels are crossing with risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and, if the circumstances of the case admit, avoid crossing ahead of the other vessel.
3A vessel is overtaking another when she is coming up with another vessel from a direction more than how many degrees abaft her beam?
A.45 degrees
B.67.5 degrees
C.90 degrees
D.22.5 degrees
Explanation: Rule 13 defines an overtaking vessel as one coming up with another from a direction more than 22.5 degrees abaft her beam—that is, in such a position that at night she would see only the sternlight of the vessel being overtaken.
4Under International Rule 34, a power-driven vessel in sight of another and altering course as authorized or required by the Rules sounds one short blast to indicate:
A.I intend to leave you on my port side
B.I am altering my course to starboard
C.I am altering my course to port
D.I am operating astern propulsion
Explanation: International Rule 34(a) uses action signals, not intent signals: one short blast means 'I am altering my course to starboard,' two short blasts 'I am altering my course to port,' and three short blasts 'I am operating astern propulsion.' A short blast is about one second.
5A vessel not under command at night exhibits which lights in addition to sidelights and a sternlight when making way through the water?
A.Three all-round red lights in a vertical line
B.Two all-round red lights in a vertical line
C.Two all-round green lights in a vertical line
D.One all-round red light over one all-round white light
Explanation: Rule 27 requires a vessel not under command to show two all-round red lights in a vertical line where they can best be seen; when making way, sidelights and a sternlight are also shown.
6In restricted visibility, a power-driven vessel making way through the water shall sound which fog signal at intervals of not more than 2 minutes?
A.Two prolonged blasts
B.One short, one prolonged, and one short blast
C.One prolonged blast
D.Five short and rapid blasts
Explanation: Rule 35 requires a power-driven vessel making way in restricted visibility to sound one prolonged blast at intervals of not more than 2 minutes.
7The danger signal of at least five short and rapid blasts is used to mean:
A.I am altering course to starboard
B.I fail to understand your intentions or actions, or I doubt whether sufficient action is being taken to avoid collision
C.I am operating astern propulsion
D.I intend to overtake you on your starboard side
Explanation: Rule 34(d) provides that when vessels in sight of one another fail to understand the intentions or actions of the other, or are in doubt whether sufficient action is being taken to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle.
8In a narrow channel under Rule 9, a vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within:
A.A traffic separation scheme
B.A deep-water route exclusively
C.A narrow channel or fairway
D.Inland waters only
Explanation: Rule 9(b) provides that a vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel which can safely navigate only within a narrow channel or fairway.
9A vessel engaged in fishing, other than trawling, exhibits which identification lights at night?
A.Green over white all-round lights
B.Two red all-round lights in a vertical line
C.White over red all-round lights
D.Red over white all-round lights
Explanation: Rule 26 requires a vessel engaged in fishing, other than trawling, to exhibit two all-round lights in a vertical line, the upper being red and the lower white (plus sidelights and sternlight when making way).
10Under Rule 10, a vessel using a traffic separation scheme shall, so far as practicable, keep clear of a traffic separation line or separation zone and shall normally join or leave a traffic lane at:
A.Right angles only, regardless of traffic
B.Any angle convenient to the destination
C.As small an angle to the general direction of traffic flow as practicable
D.Only at charted pilot boarding areas
Explanation: Rule 10 requires vessels joining or leaving a lane to do so at as small an angle to the general direction of traffic flow as practicable, and to keep clear of separation lines/zones so far as practicable.

About the USCG Master OSV Exam

The USCG Master / Chief Mate of Offshore Supply Vessels examination (NMC exam code OSV01) is the upper-level national deck-officer license examination for command and chief-mate service on offshore supply vessels on Oceans or Near Coastal routes. It is administered as a modular battery at Regional Exam Centers and covers Rules of the Road, deck general, deck safety, stability problems, navigation general, chart plot, and navigation problems. Content is framed for OSV work supporting offshore oil and gas: deck cargo, liquid mud and bulk cargo awareness, platform approaches, industrial personnel, and dynamic positioning knowledge at the multiple-choice level, together with Subchapter L and Part 11 endorsement concepts.

Assessment

OSV01: Q100 (50/90%), Q200 (70/70%), Q201 (70/70%), Q202 (10/70%), Q203 or Q204 (70/70%), Q205 (10/90%), Q206 (10/90%), Q207 Oceans only (15/80%)

Time Limit

Up to 3.5 hours per module; minimum two modules per day, all modules completed on consecutive days within the same business week

Passing Score

70% most modules; 90% Rules of the Road, Chart Plot, and Navigation Problems Near Coastal; 80% Navigation Problems Oceans

Exam Fee

$110 examination fee; ~$255 typical original upper-level total ($100 evaluation + $110 exam + $45 issuance) (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

USCG Master OSV Exam Content Outline

50 questions / 90% to pass

Q100 Rules of the Road

International (72 COLREGS) and Inland Rules: lookout, safe speed, risk of collision, head-on/crossing/overtaking, lights and shapes, sound and light signals, restricted visibility, narrow channels, TSS, and responsibilities between vessels

70 questions / 70% to pass

Q200 Deck General

Shiphandling (pivot point, transverse thrust, turning circle), anchoring and mooring, cargo stowage and securing including OSV deck cargo and bulk/liquid mud concepts, maritime law and ship's business, certificates and documents, ISM/SMS, and watchkeeping/BRM

70 questions / 70% to pass

Q201 Deck Safety

Fire classes and fixed extinguishing systems (CO2, foam), lifesaving appliances, immersion suits, EPIRB and SART, muster lists and SOLAS drills, enclosed-space entry, watertight integrity, MARPOL duties, man-overboard and abandon-ship procedures, and damage control

10 questions / 70% to pass

Q202 Stability Problems

KM−KG=GM, free surface effect (including slack mud tanks), list from weight shift, TPI/sinkage, deck-cargo rise of G, angle of loll correction, and stability-booklet use for supply-vessel loading

70 questions / 70% to pass

Q203/Q204 Navigation General

Charts and publications, IALA aids, compass error (variation/deviation), radar and electronic navigation, ECDIS/AIS awareness, tides and currents, meteorology (Buys Ballot, tropical systems), and route-specific near-coastal or oceans theory

10–15 questions / 90% or 80% to pass

Q205–Q207 Chart Plot & Navigation Problems

Chart-plot reasoning, time-speed-distance, set and drift, course to steer, running fixes, tide-table work, and oceans navigation problems (celestial intercept concepts) when on the oceans path

Integrated OSV knowledge

OSV Operations

Platform approach and stand-off, cargo-on-deck and liquid-mud transfer awareness, industrial personnel transport considerations, DP modes and reference systems at knowledge level, and Subchapter L OSV regulatory context

How to Pass the USCG Master OSV Exam

What You Need to Know

  • Passing score: 70% most modules; 90% Rules of the Road, Chart Plot, and Navigation Problems Near Coastal; 80% Navigation Problems Oceans
  • Assessment: OSV01: Q100 (50/90%), Q200 (70/70%), Q201 (70/70%), Q202 (10/70%), Q203 or Q204 (70/70%), Q205 (10/90%), Q206 (10/90%), Q207 Oceans only (15/80%)
  • Time limit: Up to 3.5 hours per module; minimum two modules per day, all modules completed on consecutive days within the same business week
  • Exam fee: $110 examination fee; ~$255 typical original upper-level total ($100 evaluation + $110 exam + $45 issuance)

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

USCG Master OSV Study Tips from Top Performers

1Drill Rules of the Road to mastery first: Q100 requires 90%, so memorize lights and shapes (Rules 23–31), head-on/crossing/overtaking (Rules 13–15), and restricted-visibility signals (Rule 35)
2Treat stability as calculation practice: KM − KG = GM, free-surface rise of G for slack tanks (especially mud), weight-shift list, and TPI sinkage until you can solve under time pressure
3For deck general, know pivot point, transverse thrust on a right-hand screw, shots of chain (15 fathoms), anchoring scope concepts, cargo securing, and OSV deck-cargo/mud transfer awareness
4For deck safety, learn fire classes A–D, CO2 release precautions (evacuate and secure ventilation), EPIRB vs SART, immersion suits, and monthly fire/abandon-ship drill expectations
5In navigation general, practice compass error (CE = variation ± deviation), radar plotting concepts, Buys Ballot's Law, and ECDIS/AIS awareness without treating them as console simulators
6Chart plot and navigation problems demand 90% (or 80% for oceans problems): automate time-speed-distance, set-and-drift triangles, and course-to-steer corrections
7Review OSV operations knowledge: platform approach and stand-off, industrial personnel, DP modes/reference systems at knowledge level, and Subchapter L context—multiple-choice only
8Use the official NMC sample Q200 Deck General and module lists (OSV01 Q100–Q207) to map your weak modules before booking the REC

Frequently Asked Questions

What is the USCG Master / Chief Mate OSV exam?

It is the upper-level U.S. national deck-officer examination (NMC exam code OSV01) for Master and Chief Mate endorsements on offshore supply vessels on Oceans or Near Coastal routes. It is taken as a modular battery at Regional Exam Centers under NMC rules and 46 CFR Part 11 officer endorsement requirements.

How many questions are on the OSV01 exam and what are the passing scores?

The published OSV01 module set lists Q100 (50 questions, 90%), Q200 (70, 70%), Q201 (70, 70%), Q202 (10, 70%), Q203 or Q204 Navigation General (70, 70%), Q205 Chart Plot (10, 90%), Q206 Navigation Problems Near Coastal (10, 90%), and Q207 Navigation Problems Oceans (15, 80%). Summing catalog modules is about 375 items; Near Coastal routes do not take Q207, and Navigation General is either Near Coastal or Oceans by route.

What subjects are tested on Master/Chief Mate OSV?

Rules of the Road (COLREGS and Inland), deck general (shiphandling, anchoring, cargo, maritime law, ship's business), deck safety (firefighting, lifesaving, GMDSS, drills, damage control), stability problems, navigation general, chart plot, and navigation problems, with OSV-relevant cargo, platform, industrial-personnel, and DP knowledge woven into the deck modules.

Do I need a further exam to raise from Chief Mate OSV to Master OSV?

Generally no. Raise of grade from Chief Mate OSV to Master OSV is typically without further professional examination once the required sea service and other credentialing requirements are met, consistent with NMC OSV path practice.

How much does the Master OSV exam cost?

Under 46 CFR 10.219, a typical upper-level original application is $100 evaluation, $110 examination, and $45 issuance (about $255 total). Since 19 January 2025, fees are paid through Pay.gov; confirm current amounts on the NMC fees page before applying.

Is remote online testing available?

No. USCG deck-officer examinations including OSV01 are administered at Regional Exam Centers (RECs). Scheduling and application follow NMC processes (including the ASAP portal for applications).

Is this practice bank the official Coast Guard exam?

No. It is a free English-language multiple-choice study aid built around the OSV01 knowledge areas. It is not an official NMC form, not a simulation of the real module structure or timing, and not a substitute for the Coast Guard's own sample examinations. The official exams are administered at Regional Exam Centers from current NMC question banks with the approved plotting sheets and reference materials.

How long is each module and how are they scheduled?

Each module must be completed within three and a half hours, and scoring time is additional. Candidates complete a minimum of two modules per day, and all modules of an examination are taken on consecutive days within the same business week. Every module, including any retests, must fall inside a 90-day examination cycle and within the one-year validity of the Approval to Test letter.

What is special about OSV stability and cargo knowledge?

OSVs commonly carry heavy deck cargo and liquid mud or bulk products with large free-surface potential. Exam-level knowledge emphasizes GM, free surface, list, deck-cargo effects on the center of gravity, platform approach seamanship, cargo securing, and industrial-personnel safety—not hands-on DP console operation.