An unhandled error has occurred. Reload X
Skip to main content

USCG Master of Vessels Up to 100 Gross Tons License Practice Test

140 questions available

The USCG Master of Vessels Up to 100 Gross Tons License is a professional credential issued by the United States Coast Guard, authorizing the holder to operate inspected and uninspected vessels of up to 100 gross tons upon oceans, near-coastal waters, inland waters, and the Great Lakes. This license represents a significant milestone in a mariner's career, signifying a comprehensive understanding of vessel operations, navigation, safety, and regulatory compliance. It is a prerequisite for command of a wide range of commercial vessels, including passenger vessels, fishing boats, research vessels, and charter operations. Earning this license validates a mariner's expertise in practical seamanship, rules of the road, chart navigation, stability, emergency procedures, and maritime law. It is recognized globally as a standard of professional competence, opening doors to advanced career opportunities, increased earning potential, and greater operational responsibility. The certification process involves rigorous assessment of sea service, completion of approved courses, passing a comprehensive written examination, and a thorough evaluation by the USCG's National Maritime Center.

140 Practice Questions
2 hours 20 minutes Practice Time
Start Practice
The bank 140 Practice questions checked against the official objectives.
qf-import140 practice questions24 answers with a checkable referenceBlueprint 1.0Bank updated 2026-05-04

Sample Questions

Try a few questions to see what the full exam is like.

24 of 140 answers carry a checkable reference.

Q100-Rules of the Road: International and Inland

Near a harbor fairway at night you see two all-round red lights in a vertical line and no sidelights. Your mate says the vessel is probably fishing and will maneuver around you. What should you conclude?

Q100-Rules of the Road: International and Inland

Your vessel is overtaking a tug and tow in a bend of an inland channel. You are more than 22.5 degrees abaft the tug's beam and intend to pass on her starboard side after the bend opens. Which statement best describes your obligation?

Q100-Rules of the Road: International and Inland

You see a vessel displaying ball-diamond-ball dayshapes while servicing an aid to navigation. Your intended passing side is close to her working gear. What is the correct interpretation?

Q100-Rules of the Road: International and Inland

Your 96 GRT vessel is stand-on in a crossing situation; the give-way vessel on your port side holds a steady bearing and closes from 1.8 NM to 0.7 NM. Passengers are on deck and a shoal limits your starboard turn. What is the correct Rules response?

Q100-Rules of the Road: International and Inland

Inland, two power-driven vessels are meeting in a narrow reach. You intend a port-to-port passage and sound one short blast. The other vessel answers with five short blasts. What should you do?

Why This Certification Opens Doors

This license is the cornerstone of professional advancement in the maritime industry. It is not merely a regulatory requirement but a mark of distinction that demonstrates proven competency, leadership, and a commitment to safety. Possessing a Master 100 GT license significantly enhances your employability and credibility with employers, charter clients, and insurance providers. It is the essential credential for assuming command, allowing you to progress from crew roles to leadership positions, thereby increasing your authority, responsibility, and earning potential. Industry recognition of this license is universal, establishing you as a qualified and trusted professional capable of ensuring the safety of vessel, crew, passengers, and the marine environment.

Exam Blueprint

01Q100-Rules of the Road: International and Inland
02Q160-Deck General
03Q161-Deck Safety
04Q162-Navigation General: Near Coastal
05Q163-Chart Plot
06Q165-Navigation-Deck General-Safety

Exam Details USCG-M100

Exam Code USCG-M100
Vendor qf-import

Frequently Asked Questions

What are the sea service requirements for the Master 100 GT license?

Requirements vary based on route (Oceans, Near Coastal, Inland, Great Lakes). Generally, you need at least 360 days of relevant service on vessels. A minimum of 90 days must have been served within the last 3 years, and at least 180 days must be on vessels over 50 gross tons. Specifics for routes like Oceans require a portion of service on ocean waters. All service must be documented on official USCG forms (719S) with corroborating evidence. It is critical to consult the latest USCG National Maritime Center guidelines for precise, up-to-date requirements for your desired route.

Can this license be upgraded to a higher tonnage (e.g., 200 GT or 500 GT)?

Yes, the Master 100 GT license serves as a foundational step. Upgrading to a Master 200 GT or 500 GT license is a common career progression. This typically requires additional sea service as Master or Mate on appropriate vessels, along with passing additional modules of the examination (e.g., Advanced Navigation for 200/500 GT). The knowledge and experience gained from holding and operating under the 100 GT license are directly applicable and often required for these upgrades.

What is the primary difference between an 'inspected' and 'uninspected' vessel in the context of this license?

An 'inspected' vessel is one that carries more than six passengers for hire and requires a Certificate of Inspection (COI) from the USCG, which mandates specific construction, equipment, and manning standards. An 'uninspected' vessel (typically cargo vessels, fishing boats, or charter vessels with 6 or fewer passengers) operates under different regulations but still requires a licensed operator. The Master 100 GT license qualifies you to command both types, which is a key advantage, allowing you to work in passenger, charter, and freight sectors.

How critical is knowledge of Stability and Trim for this exam?

Extremely critical. Stability is a core safety science for any vessel master. The exam will test your ability to apply basic stability principles, understand the information on a vessel's stability letter, calculate the effect of loading and shifting weight on trim and list, and recognize dangerous stability conditions. You must be proficient in using stability data, understanding terms like GM, righting arm, and free surface effect, as these are fundamental to preventing capsizing or downflooding.

Does this license require recurrent training or renewal?

Yes. The license itself is valid for five years. To renew, you must meet recent sea service requirements (at least 1 year of service in the last 5) and complete a physical examination. Additionally, certain endorsements (like those for passenger vessels) require periodic drills and training. Most importantly, you must hold a valid Transportation Worker Identification Credential (TWIC) and maintain compliance with USCG drug testing programs.