Revise with instant feedback: the moment you pick an answer you see whether it was right, with the explanation where available. Untimed — ideal before you sit a mock exam. Questions you miss keep coming back until you know them.
Exam-day conditions: no feedback until you submit, each module scored separately like the real test, with a full question-by-question review at the end.
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.
The free sample gives you 20 to 30 questions per module. The full bank contains every available official question, with written explanations on the popular small-vessel credentials, one-off $29, lifetime access on up to 3 devices, all credentials included.
You must pass each module separately. Most modules require 70% to pass.
The exam covers 2 modules: Deck General – Safety, Navigation General – Rivers.
This page includes free sample questions drawn from the official USCG sample examinations, with a full bank of around 112 questions across all modules available with lifetime access.
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.
No. The free practice tests work in your browser with no signup. Your score history is saved on your own device.
A selection of free questions from the official USCG sample examinations. Use the interactive modules above for timed, scored drills.
When discharging a portable CO2 fire extinguisher, why must you grasp the hose handle and NOT the discharge horn?
Which is TRUE as the temperature of the air reaches the dew point?
Which general weather conditions should you expect to find in a low-pressure system?
Which factor is most likely to impair the strength and durability of synthetic line?
Why: Ultraviolet radiation in sunlight breaks down synthetic fibers and weakens the line. Unlike natural fiber rope, synthetics are essentially immune to mildew and rot, so sunlight is their chief environmental enemy.
Fueling results in the collection of waste oil in drip pans and containers. Which is an approved method of disposing of the waste oil?
What is the period of validity of a Merchant Mariner Credential?
Why: A Merchant Mariner Credential is issued for a five-year term and must be renewed before it expires.
Which is the requirement for the name and hailing port of a documented commercial vessel?
Why: Documentation regulations require a commercial vessel's name on both bows and the name and hailing port on the stern. Nothing is ever marked on the keel.
There is a fire in the crew's quarters of your vessel. Which action should you take FIRST?
If heavy smoke is coming from the paint locker, what should be the FIRST firefighting response?
Why: Fire needs oxygen, so securing ventilation starves and contains a paint locker fire. Opening the door feeds it air and invites a flare-up; CO2 release or entry comes after the space is isolated.
How is an occluded front represented on a weather map?
A ship is on course 195° at a speed of 15 knots. The apparent wind is from 40° on the port bow, speed 30 knots. What are the direction and speed of the true wind?
Which condition(s) is(are) necessary for the formation of dew?
Why: Dew forms on clear, calm nights when surfaces radiate heat away and cool below the air's dew point; clouds blanket that radiational cooling. A surface warmer than the dew point would prevent condensation, and wind mixes the air.
Which term is given to a light that has a light period shorter than its dark period?
What is the MOST important consideration when determining how to fight an electrical fire?
To avoid error, how should you read the scale of an aneroid barometer?
If a gasoline engine turns over freely but will not start, the cause is generally __________.
Why: An engine that cranks freely has fuel, compression, or spark as the usual suspects, and in gasoline engines the ignition system (plugs, points, coil, wiring) is the most common failure. Load and lube problems would not prevent firing.
Which of the following is one of the most important safety procedures that should be adhered to prior to starting a gasoline engine on a motorboat?
Why: Gasoline vapors are heavier than air and collect in bilges and closed spaces, where a spark on start-up causes an explosion. Thorough ventilation (and running the blower) before starting is the critical safety step.
The Light List indicates that a dayboard is a type KGW. You should take which action?
Why: In the Light List dayboard codes, K identifies a range daymark. A range only works when both boards are in line, so you should look for the partner daymark to form the range.
Which is TRUE as the temperature of an air mass decreases?
Why: Cooler air can hold less water vapor, so as temperature falls toward the dew point the relative humidity rises even though the actual moisture content is unchanged.
Which would influence a magnetic compass?
Why: A magnetic compass responds to any nearby magnetic field. Ferrous metal like iron pipe distorts the field, and current-carrying electrical wiring and radio equipment create their own fields, so all three can introduce deviation.