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Master < 100 GRT to Master or Mate < 200 GRT Rivers, Revision & Practice Exams

Master < 100 GRT to Master or Mate < 200 GRT Rivers. Built from official USCG NMC sample examinations (public domain).
Content last updated 12 June 2026

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The real exam is passed module by module: Rules of the Road requires 90%, most other modules 70%. Chart-plotting modules are taken on paper and not included.

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Frequently asked questions

What score do I need to pass the Master < 100 GRT to Master or Mate < 200 GRT Rivers exam?

You must pass each module separately. Most modules require 70% to pass.

What modules are on the Master < 100 GRT to Master or Mate < 200 GRT Rivers exam?

The exam covers 1 module: Navigation and Deck General – Safety.

How many practice questions are available for Master < 100 GRT to Master or Mate < 200 GRT Rivers?

This page includes free sample questions drawn from the official USCG sample examinations, with a full bank of around 50 questions across all modules available with lifetime access.

Are these real USCG exam questions?

Every question comes from the U.S. Coast Guard National Maritime Center's published sample examinations, which are U.S. government works in the public domain. Wheelhouse Prep is not affiliated with or endorsed by the U.S. Coast Guard.

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Sample Master < 100 GRT to Master or Mate < 200 GRT Rivers practice questions

A selection of free questions from the official USCG sample examinations. Use the interactive modules above for timed, scored drills.

The most likely time for oil pollution while bunkering is when __________.

  1. hoses are disconnected and being capped
  2. first starting to receive fuel
  3. final topping off is occurring ✓
  4. hoses are being blown down

Why: Topping off is when tanks are nearly full and an overflow can occur in seconds; flow may still be substantial and the remaining ullage is small, making it the most likely moment for a spill.

Which of the following statements is/are TRUE in regard to Ro-Ro vessels' spaces that are "specially suitable for vehicles"?

  1. The spaces shall have designated smoking areas.
  2. The spaces shall be fitted with an approved fire or smoke detecting system. ✓
  3. The spaces are prohibited from being fitted with fixed CO2 fire extinguishing systems.
  4. All of the above

Which agency publishes the Light Lists?

  1. United States Coast Guard ✓
  2. National Ocean Service
  3. Oceanographic Office
  4. Army Corps of Engineers

Why: The U.S. Coast Guard publishes the Light List, describing lights, buoys, and other aids to navigation in U.S. waters. Charts and tide data come from the National Ocean Service.

Show all 10 sample questions with answers & explanations

On an inspected vessel, when may a stability test be dispensed with?

  1. Coast Guard does not have a qualified inspector available
  2. Coast Guard has the approved stability test results of a sister vessel ✓
  3. The projected cost is unreasonable
  4. The vessel is of a proven design

Which of the signals listed is required to be displayed at night while bunkering at a dock?

  1. One red light over a white light
  2. Two red lights
  3. One red light ✓
  4. One red light over a yellow light

Which is a precaution you should take before bunkering?

  1. Plug the sounding pipes
  2. Close the lids on the vents
  3. Plug the vents
  4. Plug the scuppers ✓

Static electricity may be built up by the __________.

  1. flow of petroleum through pipes
  2. spraying or splashing of petroleum
  3. settling of solids or water in petroleum
  4. All of the above ✓

In plugging submerged holes, why are rags, wedges, and other materials used in conjunction with plugs?

  1. To reduce the possibility of stress fractures
  2. To reduce the water pressure on the hull
  3. To prevent progressive flooding
  4. To reduce the water leaking around the plugs ✓

What is the purpose of a striking plate?

  1. It provides a surface for applying force on machinery
  2. It prevents valve stem over-travel
  3. It provides a landing surface for the sounding bob ✓
  4. It absorbs machinery vibration

If a vessel takes a sudden, severe list or trim from an unknown cause, which action should you take FIRST?

  1. Assume the cause is environmental forces
  2. Counterflood
  3. Determine the cause before taking countermeasures ✓
  4. Assume the shift is due to off-center loading

Why: A sudden unexplained list could be negative GM, flooding, or shifted weight, and each requires a different remedy. Counterflooding or shifting weight against the wrong cause, such as negative GM, can capsize the vessel, so find the cause first.