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100+ Free USCG Second/Third Mate Practice Questions

Prepare for the USCG Second Mate / Third Mate of Unlimited Tonnage (Oceans or Near Coastal) exam with instant access — no signup required.

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2026 Statistics

Key Facts: USCG Second/Third Mate Exam

ONC02

NMC Exam Code

USCG National Maritime Center

~300

Oceans Module Battery Questions

NMC Deck & Engineering Guide modules

90%

Rules of the Road Pass Mark

USCG NMC Q100

70%

Most Module Pass Mark

USCG NMC ONC02

11.406 / 11.407

46 CFR Second Mate / Third Mate Service Rules

Code of Federal Regulations

~$255

Typical Original Upper-Level Fees

NMC fee schedule (eval + exam + issuance)

5 years

Credential Validity

USCG Merchant Mariner Credential

ONC02 is the USCG Second Mate / Third Mate unlimited (oceans or near coastal) modular exam battery. Oceans candidates face about 300 questions across Rules of the Road (90% pass), Deck General, Deck Safety, Navigation General Oceans, Chart Plot (~87%), Navigation Problems Near Coastal (90%), and Navigation Problems Oceans (80%). Near coastal omits oceans navigation modules. Typical original upper-level fees are about $255 ($100 evaluation + $110 exam + $45 issuance) paid via Pay.gov through the NMC ASAP process. MMC validity is generally 5 years.

Sample USCG Second/Third Mate Practice Questions

Try these sample questions to test your USCG Second/Third Mate 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), every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate in the prevailing circumstances. This requirement is found in:
A.Rule 5
B.Rule 6
C.Rule 7
D.Rule 19
Explanation: Rule 5 requires a proper lookout by sight and hearing and by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.
2Under COLREGS Rule 6, factors used to determine a safe speed include all of the following EXCEPT:
A.State of visibility and traffic density
B.The nationality of the other vessel and its flag state registry
C.Maneuverability of the vessel with special reference to stopping distance and turning ability
D.At night, the presence of background light such as from shore lights or back scatter of her own lights
Explanation: Rule 6 lists visibility, traffic density, maneuverability (stopping distance and turning ability), background light at night, draft relative to available depth, wind/sea/current, and radar limitations. Nationality or flag registry is not a Rule 6 safe-speed factor.
3Under Rule 7, risk of collision shall be deemed to exist if the compass bearing of an approaching vessel:
A.Changes rapidly and continuously
B.Is always less than 10 degrees from the bow
C.Is obtained only by radar without a visual check
D.Does not appreciably change
Explanation: Rule 7(d)(i) states that such risk shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change. A steady bearing is a classic indicator of collision risk (though risk may sometimes exist even with an appreciable bearing change).
4In a crossing situation under International Rule 15, when two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall:
A.Hold course and speed as the stand-on vessel
B.Sound five short and rapid blasts and maintain course
C.Keep out of the way and, if the circumstances of the case admit, avoid crossing ahead of the other vessel
D.Alter course to port to show a green-to-green passing
Explanation: Rule 15 requires the vessel that has the other on her own starboard side to keep out of the way and, if the circumstances of the case admit, avoid crossing ahead of the other vessel. That vessel is the give-way vessel in a power-driven crossing situation.
5Under Rule 14 (head-on situation), when two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision, each shall alter her course to:
A.Port so that each shall pass on the port side of the other
B.Starboard so that each shall pass on the starboard side of the other
C.Starboard so that each shall pass on the port side of the other
D.Port only if the other vessel is more than 50 meters in length
Explanation: Rule 14 requires each power-driven vessel in a head-on situation to alter course to starboard so that each shall pass on the port side of the other (port-to-port).
6A vessel is overtaking when she is coming up with another vessel from a direction more than how many degrees abaft her beam?
A.22.5 degrees
B.45 degrees
C.67.5 degrees
D.112.5 degrees
Explanation: Rule 13 defines a vessel as overtaking when coming up with another from a direction more than 22.5 degrees abaft her beam—that is, in such a position with reference to the vessel she is overtaking that at night she would be able to see only the sternlight of that vessel but neither of her sidelights.
7Under International Rule 9 (narrow channels), 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. In addition, a vessel engaged in fishing shall not:
A.Anchor in any channel under any circumstances
B.Impede the passage of any other vessel navigating within a narrow channel or fairway
C.Display shapes when underway in a channel
D.Use radar while fishing in a fairway
Explanation: Rule 9(c) provides that a vessel engaged in fishing shall not impede the passage of any other vessel navigating within a narrow channel or fairway. Separate Rule 9 provisions address vessels less than 20 m, sailing vessels, and vessels that can safely navigate only within the channel.
8In a traffic separation scheme under Rule 10, a vessel shall so far as practicable keep clear of a traffic separation line or separation zone. A vessel crossing a traffic lane shall do so on a heading as nearly as practicable at:
A.45 degrees to the general direction of traffic flow
B.Parallel to the general direction of traffic flow
C.Right angles to the general direction of traffic flow
D.Any convenient angle if AIS is transmitting
Explanation: Rule 10(c) requires a vessel crossing a lane to do so on a heading as nearly as practicable at right angles to the general direction of traffic flow. That minimizes time in the lane.
9At night under the International Rules, a power-driven vessel underway of 50 meters or more in length shall exhibit:
A.Sidelights and a sternlight only
B.A forward masthead light, a second masthead light abaft of and higher than the forward one, sidelights, and a sternlight
C.An all-round white light and sidelights only
D.Two all-round red lights in a vertical line, sidelights, and a sternlight
Explanation: Rule 23 requires a power-driven vessel underway to show masthead light(s), sidelights, and a sternlight. Vessels 50 m or more must show a second masthead light abaft of and higher than the forward one (except that a vessel less than 50 m is not obliged to exhibit the second masthead light but may do so).
10A vessel not under command (NUC) underway at night exhibits which lights in addition to sidelights and a sternlight when making way through the water?
A.Two all-round green lights in a vertical line
B.Three all-round lights in a vertical line: red, white, red
C.Two all-round lights in a vertical line, the upper white and the lower red
D.Two all-round red lights in a vertical line
Explanation: Rule 27(a): a vessel not under command shall exhibit two all-round red lights in a vertical line where they can best be seen, and when making way through the water, sidelights and a sternlight as well. When not making way, sidelights and sternlight are not shown.

About the USCG Second/Third Mate Exam

The USCG Second Mate / Third Mate of Unlimited Tonnage examination (NMC exam code ONC02) is the officer-of-the-watch deck license exam for ocean or near-coastal self-propelled vessels of unlimited tonnage. It is taken by mariners meeting sea-service and training requirements under 46 CFR 11.406 (Second Mate), 46 CFR 11.407 (Third Mate), and related Subchapter B officer endorsement rules. Content emphasizes watchkeeping, cargo operations, collision regulations, deck safety, and navigation—not pure master-level management—across the modular Q100–Q117 battery.

Assessment

Modular REC battery (ONC02). Core modules: Q100, Q111, Q112, plus navigation general and navigation-problem modules by route (near coastal vs oceans). Not a single-sitting exam; candidates typically complete modules over one or more sessions.

Time Limit

Up to 3.5 hours per module

Passing Score

70% most modules; 90% Rules of the Road and Nav Problems Near Coastal; ~87% Chart Plot; 80% Nav Problems Oceans

Exam Fee

$110 exam fee; about $255 typical original upper-level total (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

USCG Second/Third Mate Exam Content Outline

15% of practice bank

Rules of the Road

COLREGS and Inland Rules for lookout, safe speed, risk of collision, steering and sailing situations, lights and shapes, sound signals, narrow channels, TSS, and restricted visibility (official Q100 requires 90%).

25% of practice bank

Deck General

Shiphandling, anchoring and mooring, cargo stowage and securing, ship construction, watchkeeping and bridge resource management, documentation, and OOW deck operations (Q111).

25% of practice bank

Deck Safety

Firefighting and fire classes, fixed extinguishing systems, lifesaving appliances, GMDSS distress tools, MARPOL, man-overboard, damage control, and emergency drills (Q112).

20% of practice bank

Navigation General

Charts, compass error, ATON, tides and weather, radar/AIS/ECDIS, and oceans celestial fundamentals for second/third mate navigation general modules.

15% of practice bank

Navigation Problems & Chart Plot

Time-speed-distance, set and drift, course to steer, tide calculations, sailings concepts, and chart-plotting problem types with high module cutoffs.

How to Pass the USCG Second/Third Mate Exam

What You Need to Know

  • Passing score: 70% most modules; 90% Rules of the Road and Nav Problems Near Coastal; ~87% Chart Plot; 80% Nav Problems Oceans
  • Assessment: Modular REC battery (ONC02). Core modules: Q100, Q111, Q112, plus navigation general and navigation-problem modules by route (near coastal vs oceans). Not a single-sitting exam; candidates typically complete modules over one or more sessions.
  • Time limit: Up to 3.5 hours per module
  • Exam fee: $110 exam fee; about $255 typical original upper-level total

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 Second/Third Mate Study Tips from Top Performers

1Treat Rules of the Road as a separate mastery project—you need 90%, so drill lights, shapes, sound signals, and every steering-and-sailing scenario until recall is automatic.
2Build a COLREGS vs Inland comparison sheet for whistle signals, narrow-channel overtaking, and any inland-only differences that appear on Q100.
3For deck general, focus on OOW duties: cargo securing principles, watch handover, anchoring scope, pivot point/transverse thrust, and key USCG forms (CG-719B/K/P, CG-2692).
4For deck safety, memorize fire classes A–D, fixed CO2 room precautions, EPIRB (406 MHz) vs SART roles, SOLAS drill cadence, and Williamson/Anderson/Scharnow MOB turn concepts.
5Practice navigation arithmetic daily: distance = speed × time, set-and-drift triangles, compass error (TVMDC), and distance to horizon ≈ 1.17√h(ft).
6On oceans modules, know celestial fundamentals: refraction is greatest near the horizon, amplitude on the celestial horizon for compass error, LAN for latitude, and intercept = Ho − Hc.
7Check the current NMC calculator policy before you test: since the December 2, 2024 policy letter, RECs allow a programmable calculator provided you clear all programs and memory, bring the manufacturer's instructions showing how to clear it, and demonstrate that to the examiner — otherwise a TI-30XIIS is issued to you. One calculator only; smart watches and other electronic devices are not permitted.
8Simulate module pacing with timed 50–70 question blocks so 3.5-hour windows feel routine.

Frequently Asked Questions

What is the USCG Second Mate / Third Mate Unlimited exam?

It is the NMC modular knowledge exam (code ONC02) for Second Mate or Third Mate of unlimited tonnage on ocean or near-coastal self-propelled vessels. Sea service and training requirements are set in 46 CFR Subchapter B — 11.406 for Second Mate and 11.407 for Third Mate — together with related officer endorsement rules.

How many questions are on the ONC02 exam?

The battery is modular, not a single fixed paper. The oceans path is roughly 300 questions across Q100 (50), Q111 (70), Q112 (70), Q114 (70), Q115 (15), Q116 (10), and Q117 (15). Near coastal uses Q113 instead of Q114 and typically omits Q117.

What passing scores are required?

Most modules require 70%. Rules of the Road requires 90%. Navigation Problems Near Coastal requires 90%. Chart Plot is about 87%. Navigation Problems Oceans requires 80%. Always confirm the score printed on your NMC sample/module materials.

How much does the exam cost?

For a typical original upper-level officer endorsement, NMC fees are commonly $100 evaluation, $110 examination, and $45 issuance (about $255 total). Fees are paid through Pay.gov. Confirm the current schedule at the NMC fees page before applying.

How long is each module?

Coast Guard sample exams commonly list up to 3.5 hours per module. Total testing time depends on which modules you take and whether you complete them in one REC visit or multiple sessions.

What is the difference between oceans and near coastal routes?

Both paths share Rules, Deck General, and Deck Safety. Oceans adds Navigation General Oceans and Navigation Problems Oceans (celestial and ocean sailings concepts). Near coastal uses Navigation General Near Coastal and omits the oceans navigation-problems module.

Is this practice bank an official exam simulation?

No. It is a free English multiple-choice study aid covering the modular battery at OOW (second/third mate) level. Official exams are administered by the Coast Guard at Regional Exam Centers using current NMC question banks and plot sheets.

How long is the MMC valid after I pass?

Merchant Mariner Credentials are generally issued for 5 years and must be renewed under current Coast Guard credentialing rules.