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 3 modules: Deck General, Deck Safety, Navigation General.
This page includes free sample questions drawn from the official USCG sample examinations, with a full bank of around 136 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.
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A selection of free questions from the official USCG sample examinations. Use the interactive modules above for timed, scored drills.
Which is the BEST way to reduce your wake in a narrow channel?
Your vessel is moored portside to and you are taking over the Deck Watch. Which item has the most impact on the safety of the vessel and crew?
Which level of accuracy can be obtained utilizing the U.S. Coast Guard's Maritime Differential GPS in an established coverage area?
Why: The Coast Guard's maritime Differential GPS broadcast corrections that provided 10-meter accuracy (typically better) throughout its established coverage areas.
What is the standard atmospheric pressure in millibars?
The light characteristic of flashing is used in the Aids to Navigation System on the Western Rivers. Which example is required to utilize this characteristic?
Who must approve the vessel's trim and stability booklet?
Why: For U.S. inspected vessels the trim and stability booklet must be approved by the Coast Guard, which reviews the stability data and inclining experiment results during plan approval.
A temporary wire eye splice made with three wire rope clamps will hold approximately what percentage of the total rope strength?
How many months after its expiration date may a Coast Guard credential be renewed without retaking the complete exam?
The water in which a vessel floats provides vertical upward support. Which term is regarded as the point through which this support is assumed to act?
Why: The buoyant force acts through the center of buoyancy, the geometric center of the underwater volume. The center of gravity is where weight acts downward, and the center of flotation is the center of the waterplane.
Which defines the function of a spark arrestor?
Why: A spark arrestor traps glowing carbon particles in an engine's exhaust, preventing them from escaping the exhaust system and igniting flammable vapors or materials nearby.
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.
You have another ship overtaking you close aboard to starboard. You have 3 radar targets bearing 090° relative at ranges of .5-mile, 1 mile, and 1.5 miles. Which term is given to these unwanted echoes?
To find the specific phase characteristic of a lighthouse on a sound of the United States you would use which reference?
Why: The Light List gives each light's complete characteristic, including rhythm, period, and colors, in more detail than the chart abbreviation. The Coast Pilot describes waters generally but is not the reference for light characteristics.
You are berthed at a cargo facility where you have just completed discharging a dangerous cargo. You must complete topside repairs involving hot-work before sailing. Which of the following statements is TRUE?
Which clouds are described as high clouds, composed of small white flakes or scaly globular masses, and often banded together to form a "mackerel sky"?
A ballasted vessel sinks enroute to a dry dock. Under these circumstances, the vessel's owner can claim which loss?
Where a propeller shaft passes through the hull, which device prevents water from entering the hull?
Why: The stuffing box surrounds the shaft where it penetrates the hull; packing compressed by a gland seals against sea water while still letting the shaft rotate. A sea cock is a hull valve, not a shaft seal.
A fire of escaping liquefied flammable gas is best extinguished by which action?
In North America, which direction do the majority of the weather systems move?
Why: North America lies in the belt of prevailing westerlies, so weather systems are steered generally from west to east across the continent. That is why forecasts watch conditions to your west.
According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northwest wind, where is the center of low pressure located?
Why: Buys Ballot's law: in the Northern Hemisphere, face away from the wind and the low is on your left. With wind from the northwest at your back, your left hand points northeast.
Which visual distress signal is acceptable for daylight use only?
Why: Orange smoke is visible only by day, so hand-held orange smoke signals are approved for daylight use only. Red flares, hand-held or aerial, are approved for both day and night.
What is one effect of running a diesel engine at too cool a temperature?
The Federal Water Pollution Control Act requires the person in charge of a vessel to immediately notify the Coast Guard as soon as he knows of any oil discharge. Failure to notify the Coast Guard can lead to a monetary fine and imprisonment up to what duration?
Why: The Federal Water Pollution Control Act makes failure to immediately report a known oil discharge a criminal offense punishable by fine and imprisonment up to five years.
What is the minimum size required before a vessel can be documented?
Why: Federal vessel documentation requires a minimum of 5 net tons. Eligibility is measured by tonnage, not length, and 100 gross tons is far above the threshold.
Which extinguishing agent is/are suitable to combat a class B fire in an engine compartment?
Why: Class B flammable liquid fires are fought by smothering; carbon dioxide, dry chemical, and foam all exclude oxygen effectively, so any of them may be used in an engine compartment.
Which is TRUE concerning the stowage of life jackets?
Why: In an emergency there is no time to unlock containers or go to a central point. Regulations require life jackets to be readily accessible so each person can reach one quickly from work and berthing areas.
What is the number of fire extinguishers required on an uninspected "motor vessel" based on?
A fire starting by spontaneous combustion can be expected in which condition?
What is LEAST likely to cause ignition of fuel vapors?
Where can the deepest water when rounding a bend in a river be located?