PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free USCG Master/Mate GLI 100 Practice Questions

Prepare for the USCG Master or Mate Great Lakes and Inland of Less Than 100 GRT 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...

Same family resources

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.

USCG OUPV Six-Pack Captain License

Practice QuestionsStudy GuideCheat SheetFlashcards1 video1 blog

USCG Master 100-Ton Captain License

Practice QuestionsStudy Guide

USCG Barge Supervisor (MODU)

Practice Questions

USCG Offshore Installation Manager (OIM)

Practice Questions

USCG Able Seafarer (Able Seaman) Limited

Practice Questions

USCG Able Seafarer (Able Seaman) Special

Practice Questions

More From This Family

Videos and articles for deeper review.

VideoFREE USCG OUPV Six-Pack Captain License Guide 2026: Pass First TryArticleFREE USCG OUPV Six-Pack Captain License Guide 2026: Pass First Try27 min read
2026 Statistics

Key Facts: USCG Master/Mate GLI 100 Exam

GLI06

NMC Exam Code

NMC Examinations

50

Questions per Core Deck/Nav Module

USCG Deck Guide Q347–Q349

10

Chart Plot Questions (Q350)

NMC GLI06 listing

90%

Rules & Chart Plot Pass Score

USCG Deck Guide

70%

Deck/Nav Module Pass Score

USCG Deck Guide

$240

Typical Original Total Fee

Evaluation + exam + issuance

GLI06 Master or Mate Great Lakes and Inland less than 100 GRT is modular. Modules include Rules of the Road (50 at 90%), Q347–Q349 Deck General, Deck Safety, and Navigation General GLI (50 each at 70%), Q350 Chart Plot (10 at 90%), and Q352 as assigned. Lower-level original fees are about $100+$95+$45 under 46 CFR 10.219. This free bank is an English MCQ study aid focused on the assessable knowledge of the GLI06 path.

Sample USCG Master/Mate GLI 100 Practice Questions

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

1Under Inland Rule 34(e), a vessel nearing a bend where approaching vessels may be hidden by an intervening obstruction shall sound:
A.One prolonged blast, which is answered with a prolonged blast by any approaching vessel within hearing
B.Two short blasts, which need not be answered
C.Five short and rapid blasts until the bend is cleared
D.Three short blasts followed by one prolonged blast
Explanation: Inland Rule 34(e) (33 CFR 83.34(e)) requires one prolonged blast when nearing a bend or an area of a channel where other vessels may be obscured. Any approaching vessel within hearing around the bend or behind the obstruction must answer with a prolonged blast. Rule 9(f) reinforces this by requiring particular alertness and caution at such places.
2Under Rule 19, a vessel that hears apparently forward of her beam the fog signal of another vessel, where risk of collision has not been ruled out, shall:
A.Reduce speed to the minimum at which she can be kept on course, taking all way off if necessary
B.Hold her speed and alter boldly to port
C.Continue at safe speed without any further reduction
D.Sound the doubt signal and stop her engines only after sighting the other vessel
Explanation: Rule 19(e) requires a vessel that hears the fog signal of another vessel apparently forward of her beam, or that cannot avoid a close-quarters situation with a vessel forward of the beam, to reduce speed to the minimum at which she can be kept on her course, to take all way off if necessary, and in any event to navigate with extreme caution until the danger of collision is over.
3Inland Rule 34(b) permits whistle signals to be supplemented by light signals. Those light signals must use:
A.An all-round white or yellow light visible at a minimum range of 2 miles, with each flash about 1 second long
B.A flashing blue light visible at a minimum range of 5 miles
C.A red all-round light synchronized with the sidelights
D.Any handheld spotlight aimed at the other vessel's bridge
Explanation: Inland Rule 34(b) (33 CFR 83.34(b)) allows one flash to mean 'I intend to leave you on my port side', two flashes 'on my starboard side', and three flashes astern propulsion. Each flash lasts about 1 second, and the light, if fitted, must be one all-round white or yellow light visible at least 2 miles and synchronized with the whistle.
4Under Inland Rule 15(b), on the Great Lakes, Western Rivers, or waters specified by the Secretary, a power-driven vessel crossing a river shall:
A.Keep out of the way of a power-driven vessel ascending or descending the river
B.Stand on, because the ordinary crossing rule always governs
C.Keep out of the way only of vessels descending the river
D.Sound five short blasts and hold her course until answered
Explanation: Inland Rule 15(b) (33 CFR 83.15(b)) overrides the ordinary starboard-side crossing rule on the Great Lakes, Western Rivers, and specified waters: a power-driven vessel crossing a river must keep out of the way of a power-driven vessel ascending or descending it, regardless of which side the traffic is on. Ferry and workboat traffic crossing a river is therefore always the give-way vessel.
5A vessel aground at night shall exhibit the anchor lights and, if practicable, in addition:
A.Two all-round red lights in a vertical line, and by day three balls in a vertical line
B.Two all-round green lights in a vertical line, and by day one ball
C.Three all-round white lights in a vertical line, and by day a diamond
D.A flashing yellow light, and by day a cylinder
Explanation: Inland Rule 30(d) (33 CFR 83.30(d)) requires a vessel aground to show the anchor lights plus, where they can best be seen, two all-round red lights in a vertical line, and three balls in a vertical line by day. A vessel of less than 12 metres in length aground is not obliged to display those additional lights and shapes.
6Under Rule 35, a vessel of less than 12 metres in length operating in restricted visibility:
A.Is not obliged to give the prescribed signals, but must then make some other efficient sound signal at intervals of not more than 2 minutes
B.Is completely exempt from making any sound signal at all
C.Must sound the full bell and gong signals like a vessel of 100 metres or more
D.Must sound five short and rapid blasts every minute
Explanation: Rule 35(j) (33 CFR 83.35(j)) relieves a vessel of less than 12 metres of the prescribed fog signals, but if she does not give them she must make some other efficient sound signal at intervals of not more than 2 minutes. Rule 35(i) applies the same idea to the bell signal for vessels of 12 metres or more but less than 20 metres.
7Under Rule 9(d), a vessel must not cross a narrow channel or fairway if such crossing impedes the passage of a vessel that can safely navigate only within the channel. If the vessel confined to the channel is in doubt about the crossing vessel's intentions she:
A.Uses the doubt signal of at least five short and rapid blasts
B.Sounds one prolonged blast and holds her speed
C.Must give way to the crossing vessel immediately
D.Sounds three short blasts to warn the crossing vessel
Explanation: Rule 9(d) (33 CFR 83.09(d)) prohibits crossing a narrow channel if it impedes a vessel that can navigate safely only within it, and directs the confined vessel to use the Rule 34(d) doubt signal—at least five short and rapid blasts—if she is in doubt about the crossing vessel's intentions. Rule 9(b) applies the same not-impede duty to vessels under 20 metres and to sailing vessels.
8Under Rule 33, which sound-signalling equipment must a vessel of 20 metres or more but less than 100 metres in length carry?
A.A whistle and a bell
B.A whistle only
C.A whistle, a bell, and a gong
D.No equipment, provided a handheld air horn is aboard
Explanation: Rule 33 (33 CFR 83.33) sets three thresholds: a vessel of 12 metres or more must carry a whistle, a vessel of 20 metres or more must carry a bell in addition, and a vessel of 100 metres or more must also carry a gong whose tone cannot be confused with the bell. A vessel under 12 metres need not carry these appliances but must have some other means of making an efficient sound signal.
9Rule 8(e) addresses the case where more room is needed to assess a situation or avoid collision. It provides that a vessel shall:
A.Slacken her speed or take all way off by stopping or reversing her means of propulsion
B.Maintain speed so the other vessel can predict her track
C.Alter course only, because speed reductions confuse other vessels
D.Call the other vessel on VHF before taking any action
Explanation: Rule 8(e) states that if necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion. Rule 8(a) and 8(b) add that any action must be positive, made in ample time, and large enough to be readily apparent to another vessel observing visually or by radar.
10Under Rule 20, the Rules concerning lights must be complied with:
A.From sunset to sunrise, and also from sunrise to sunset in restricted visibility
B.Only between midnight and 0400 in commercial waterways
C.Only when another vessel is within two miles
D.Only from sunset to sunrise, with no daytime requirement in any conditions
Explanation: Rule 20 requires the lights to be exhibited from sunset to sunrise, and during those hours no other lights may be shown that could be mistaken for the prescribed lights or impair their visibility. The prescribed lights must also be exhibited from sunrise to sunset in restricted visibility, and may be shown in any other circumstances when it is deemed necessary.

About the USCG Master/Mate GLI 100 Exam

The USCG Master or Mate Great Lakes and Inland of Less Than 100 GRT examination (NMC exam code GLI06) is the national deck knowledge path for limited 100 GRT officer service on Great Lakes and inland waters. Core modules include Rules of the Road (Q100), Deck General (Q347), Deck Safety (Q348), Navigation General Great Lakes and Inland (Q349), Chart Plot (Q350), and Q352 as assigned by NMC.

Assessment

GLI06: Q100 Rules of the Road International and Inland (50, 90%); Q347 Deck General (50, 70%); Q348 Deck Safety (50, 70%); Q349 Navigation General Great Lakes and Inland (50, 70%); Q350 Chart Plot (10, 90%); Q352 related Navigation/Deck as assigned per NMC listing for Master or Mate less than 100 GRT.

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; 90% Chart Plot (Q350)

Exam Fee

$95 examination fee; ~$240 typical original lower-level total ($100 evaluation + $95 exam + $45 issuance) (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

USCG Master/Mate GLI 100 Exam Content Outline

~25%

Rules of the Road

Collision regulations for inland/GL 100 GRT officers.

~25%

Deck General

Seamanship and watchkeeping (Q347).

~25%

Deck Safety

Safety equipment and emergencies (Q348).

~20%

Navigation General

Great Lakes and inland navigation fundamentals (Q349).

~5%

Chart Plot

Plotting and navigation calculations (Q350).

How to Pass the USCG Master/Mate GLI 100 Exam

What You Need to Know

  • Passing score: 70% most modules; 90% Rules of the Road; 90% Chart Plot (Q350)
  • Assessment: GLI06: Q100 Rules of the Road International and Inland (50, 90%); Q347 Deck General (50, 70%); Q348 Deck Safety (50, 70%); Q349 Navigation General Great Lakes and Inland (50, 70%); Q350 Chart Plot (10, 90%); Q352 related Navigation/Deck as assigned per NMC listing for Master or Mate less than 100 GRT.
  • 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: $95 examination fee; ~$240 typical original lower-level total ($100 evaluation + $95 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/Mate GLI 100 Study Tips from Top Performers

1Overprepare for Rules of the Road because those modules require 90% to pass.
2Know when Inland Rules differ from COLREGS (sound signals, lights, narrow channels, Western Rivers/Great Lakes special rules).
3Drill chart-plot routines for Q350: largest scale chart, regular fixes, set and drift, and standard plotting symbology—pass is 90% on only 10 questions.
4Practice speed-time-distance and course-to-steer arithmetic until automatic under time pressure.
5Study Great Lakes weather, ice, seiches, and inland aids if your route includes Great Lakes waters.
6Take timed sets of 50 questions to match REC module length for Q347–Q349.
7Memorize required lights, shapes, and sound signals for power-driven vessels, towing, fishing, and restricted-visibility situations.
8Review stability, damage control, firefighting, and abandon-ship procedures for deck safety modules.
9Confirm whether your application needs Q100 (Inland and International) to avoid a COLREGS limitation.
10Study the GLI06 module list on the NMC examinations pages; do not confuse GLI06 with Near Coastal 100-ton (ONC06) modules.

Frequently Asked Questions

How many questions are on the USCG GLI06 exam?

GLI06 is modular for Master or Mate less than 100 GRT on Great Lakes and inland routes. Published modules include Rules of the Road (Q100, 50), Deck General (Q347, 50), Deck Safety (Q348, 50), Navigation General GLI (Q349, 50), Chart Plot (Q350, 10), and Q352 as assigned. Exact totals depend on the path requested.

What passing score do I need?

Most modules require 70%. Rules of the Road requires 90%. Chart Plot (Q350) requires 90%.

How much does the exam cost?

Under 46 CFR 10.219, a typical original lower-level officer path is about $100 evaluation, $95 examination, and $45 issuance. Medical, drug testing, and training costs are separate. Pay via Pay.gov.

Can I take the exam remotely?

No. These deck officer modules are administered in person at U.S. Coast Guard Regional Exam Centers (RECs). There is no approved remote-testing option for these endorsements.

Is GLI06 the same as the Near Coastal 100-ton Master exam?

No. GLI06 is Master or Mate Great Lakes and Inland of less than 100 GRT. Near Coastal Master less than 100 GRT uses a different NMC path (often associated with ONC06 / uscg-master-100). Do not mix route-specific modules or assume one credential covers the other route.

What is the difference between Inland-only and Great Lakes and Inland Rules modules?

For Great Lakes and Inland routes, Rules of the Road is Inland and International (Q100). For Inland routes, applicants may take Inland-only Rules when allowed, but Inland-only Rules result in a geographic COLREGS limitation on the MMC unless Q100 is also completed (46 CFR 11.430).

Are open-book renewal exercises the same as the original modules?

Renewal open-book exercises (for example, Q351 and other renewal papers listed in the Deck Guide) are separate from original GLI06 knowledge modules. This bank focuses on original-module knowledge.

What calculator can I bring?

The NMC policy letter of December 2, 2024 superseded the earlier TI-30XIIS-only rule. At a Regional Exam Center you may use a programmable calculator with memory if all programs and memory are cleared before entry and you can demonstrate clearing with the manufacturer's instructions. If the examiner cannot confirm the device is cleared, a TI-30XIIS is provided instead. Only one calculator is allowed; other electronics including smart watches are not permitted.

Is this free practice bank an official Coast Guard exam?

No. This is a free English-language multiple-choice study aid for exam prep. Official modules are administered by the Coast Guard at RECs and may include chart-plot and calculation items that this bank approximates with knowledge and calculation MCQs.