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 – Rivers.
This page includes free sample questions drawn from the official USCG sample examinations, with a full bank of around 148 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.
Your vessel is disabled and in imminent danger of grounding on a lee shore. The Master agrees to salvage services using Lloyd's Open Form of Salvage Agreement. Which is TRUE?
What is the difference between net tonnage and gross tonnage?
Under U.S. law, what is the penalty for assaulting the Master?
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?
What quality of a diesel fuel is most significant for efficient combustion?
A situation has occurred where it becomes necessary for you to be towed. What action should be taken to prevent your vessel from yawing?
Why: Shifting weight aft sets the stern deeper, increasing drag aft so the towed vessel trails straight behind the towline like a weathervane instead of sheering from side to side.
An electronic depth finder operates on which principle?
Which is the reference datum used in determining the heights of land features on most charts?
Which type of precipitation occurs only in thunderstorms with strong convection currents that convey raindrops above and below the freezing level?
Which agency publishes the Light Lists?
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.
What happens to the barometric pressure after a cold front passes?
On an inspected vessel, when may a stability test be dispensed with?
A block and tackle is "rove to advantage". What does this mean?
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.
According to the Lifesaving regulations in Subchapter W, fire and abandon ship drills must be held within 24 hours of leaving port if the percentage of the crew that has not participated in drills aboard that particular vessel in the prior month exceeds which percentage?
Why: Subchapter W requires fire and abandon-ship drills within 24 hours of leaving port whenever more than 25 percent of the crew did not participate in drills aboard that vessel during the previous month.
You are at sea and have received a General Emergency message announcing the outbreak of war in Europe. You are directed to comply with the instructions in NGA (NIMA) PUB 117, Chapter Eight. Which statement is TRUE?
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.
When patching holes in the hull, how can pillows, bedding, and other soft materials be used?
Which term describes a light, feathery deposit of ice by sublimation of water vapor directly into the crystalline form on objects whose temperatures are below freezing?
Which of the following is the most accurate method of determining gyrocompass error while underway?
Quadrantal error in a gyrocompass has its GREATEST effect on which of the following?
Your vessel is on course 180°T speed 22 knots. The apparent wind is from 70° off the port bow, speed 20 knots. What are the true direction and speed of the wind?
Which cloud commonly produces a halo about the Sun or Moon?
The scuppers had been plugged as required at the time a small oil spill occurs on deck from a leaking dresser coupler. After shutting down the transfer, the engine room should first be informed and then which action should be taken?
If you are forced to abandon ship in a rescue boat, which action should you take?
If you see an individual fall overboard, which action(s) should you take?
In relation to the turning circle of a ship, which describes the term "kick"?
Normally, your vessel is on a voyage of three months duration. How many sanitary inspections are required to be conducted during the voyage?
You are loading in a port subject to the winter load line mark and bound for a port subject to the tropical load line mark. You will enter the summer zone after steaming four days, and you will enter the tropical zone after a total of twelve days. You will consume 39 tons of fuel, water, and stores per day. The hydrometer reading at the loading pier is 1.025, and the average TPI is 49. What is the minimum freeboard required at the start of the voyage? Reference Table BL-0010 below.
In the context of shiphandling, what would be the definition of shallow water?
Why: For shiphandling, shallow water effects (squat, sluggish steering) become significant when depth is less than about one and a half times the vessel's draft. The deeper definitions in the other options are not the accepted rule.