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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.
MODU stands for Mobile Offshore Drilling Unit.
You must pass each module separately. Most modules require 70% to pass.
The exam covers 10 modules: OIM – Deck General – Safety, OIM Unrestricted, OIM Surface Units Underway, OIM Surface Units on Location, OIM Bottom Bearing Units Underway, OIM Bottom Bearing Units on Location, Barge Supervisor – Deck General – Safety, Barge Supervisor – MODU Operations, BCO – Deck General – Safety, BCO – MODU Operations.
This page includes free sample questions drawn from the official USCG sample examinations, with a full bank of around 499 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.
The distress message of a ship should include considerable information which might facilitate the rescue. Which is TRUE concerning the information?
Where there are multiple accident victims, which type of injury should be the first to receive emergency treatment?
Which is TRUE of a distress signal?
When a rescue vessel approaches a survival craft in heavy seas, which action should the person in charge of the survival craft take?
What is the spoken emergency signal for a distress signal over a VHF radio?
You will find daily information about the duration of slack water in a port on the Atlantic Coast in which publication?
Ascending and descending air masses with different temperatures is part of an important heat transmitting process in our atmosphere. Which term is given to this process?
Which term(s) are in the category of "oil" as used in the Oil Pollution Regulations?
Why: The pollution regulations define 'oil' broadly: fuel oil, sludge, oil refuse, and oil mixed with wastes all fall within the term, so discharge of any of them is regulated.
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.
What should you do if you have transmitted a distress call a number of times on channel 16 and have received no reply?
Plain language is usually used on marine weather __________.
Which is a characteristic of warm air masses?
As a last resort, what can a tourniquet be used for?
Weather systems in the middle latitudes generally travel in which direction?
If you find a victim that is unconscious. What vital signs is an immediate threat to life?
When an Official logbook is not required, an unofficial logbook is required to be kept aboard for review by a marine inspector for __________.
Why: When no official logbook is required, the vessel must still keep an unofficial log of required entries aboard, available for review by a marine inspector, for twelve months.
When oily ballast has been pumped overboard, an entry must be made in which log?
If you observe any situation which presents a safety or pollution hazard during fuel transfer operations, what action should you take FIRST?
You are in a lifeboat broadcasting a distress message. What information would be essential to your rescuers?
Which extinguishing agent is most effective on a mattress fire?
Why: A mattress fire is a deep-seated Class A fire. Water soaks into the material, cooling below ignition temperature throughout. Gas agents like CO2 or Halon only smother the surface, so the fire can rekindle inside.
Which is TRUE if passengers are on board when an abandon ship drill is carried out?
If the current and wind are in the same direction, what does the sea surface represent concern the true wind speed?
What shall be conducted during a fire and boat drill?
Why: Fire and boat drill requirements include operating all watertight doors in the vicinity of the drill so crews can work them in an emergency. Pumps are started but outlets are not all opened.
Which is TRUE of the velocity of the current in large coastal harbors?
Why: Currents in large coastal harbors are strong enough to matter but are regular and tide-driven, so their times and velocities are predicted in the Tidal Current Tables.
If you are required to jump from any height from your vessel when should the external flotation bladder of an immersion suit be inflated?
Why: Inflating the bladder before jumping risks neck and internal injury on water impact and can damage the bladder. Jump with it deflated, then inflate once in the water to keep your head elevated.
How is the external flotation bladder of an immersion suit inflated?
It is desirable that a vessel encountering hurricane or typhoon conditions sends weather reports to the closest meteorological service at which time interval?
When is firefighting foam most effective?
All of the following are recognized distress signals under the Navigation Rules EXCEPT which signal?
A man aboard a vessel, is signaling by raising and lowering his outstretched arms to each side. What does this signal indicate?
Which statement describes the primary process by which fires are extinguished by dry chemical?
You are preparing to load fuel oil on a vessel of 300 gross tons constructed after June 30, 1974. Before loading, which statement is TRUE concerning fuel oil tank vents?
Beyond the area of state ownership in the U.S. outer continental shelf, the right to drill is controlled by the __________.
Apparent wind speed blowing across a MODU under tow can be measured by a(n) __________.
In an emergency, if you must jump from a MODU, what is the best procedure to follow?
What is the shift in the longitudinal center of gravity if 200 short tons are discharged from 30 feet forward of amidships on a MODU with LCG 1.5 feet forward of amidships, and displacement 9,000 short tons?
The COASTAL DRILLER is loaded as shown in the Sample Load Form #1 (Rig Move). What is the margin on the maximum allowable KG if winds increase to greater than 70 knots, and the TOC is changed to the recommended value?
The DEEP DRILLER is moored in 600 feet of water. The tension on anchor line #8 is 190 kips. What is the vertical component of chain tension for that line?
Adding the FSCL to KG yields __________.
Failure of both port ballast pumps on the DEEP DRILLER prevents their use. To deballast from tank 1P, you may use the __________.
The element used to keep weight on the bit at a constant value in spite of up-and-down movement of a MODU during floating drilling operations is the heave or drill string __________.
Buoyancy associated with empty or partly empty ballast tanks in the mat of a mat supported jack-up MODU during jacking operations can cause __________.
The wire ropes of the riser tensioning system are attached to the __________.
If a man falls overboard from a rig under tow, you should FIRST __________.
When a semisubmersible rig under tow experiences pounding on the forward transverse brace, the surest way to alleviate the condition would be to __________.
For the purposes of the International Rules of the Road, a non-self-propelled mobile offshore drilling unit under tow is considered to be a __________.
What danger is presented if a waterspout passes over a MODU?
A hydraulic accumulator aboard a MODU is designed to __________.
While in 150 feet water depth when the pitch angle of the COASTAL DRILLER is 1 degree, the platform pitch period for going on location should be longer than __________.
A series of trays with sieves that vibrate to remove cuttings from the circulating fluid in rotary drilling operations is called the __________.
A heavy steel device that is set on the sea floor and used as a drilling template in offshore drilling operations is called a __________.
The wooden plug inserted in the vent of a damaged tank of a MODU should be removed in case it is decided to __________.
What is a pinion in a jacking system?
The overturning forces acting on a floating jack-up are generally dominated by __________.
Compliance with the terms of the load line certificate on a MODU is the responsibility of the __________.
Which of the following would be the most probable location to encounter explosive and flammable gasses on a MODU?
While the COASTAL DRILLER is elevated, the out-of-level alarm indicates that hull inclination exceeds 0.3°. What should you do?
A hurricane has recurved to the northeast and its forward speed is 20 knots. Your MODU is located 600 miles northeast of the hurricane's center. How long will it take for the hurricane center to reach your position if it holds its present course and speed?
Aboard the DEEP DRILLER, the bilge pumps take suction from the pump rooms, cofferdam, void area, access trunk, and which other area?
The DEEP DRILLER is loaded as shown in the Sample Load Form #1 (Transit). If weather conditions make it necessary to ballast down to survival, how much ballast would be required?
The DEEP DRILLER is loaded as shown in the Sample Load Form #1 (Transit). What is the new height of the center of gravity corrected for longitudinal free surface effects if the entire contents of Saltwater Ballast Tanks 1P and 1S are discharged?
On the DEEP DRILLER, among the valves to open when transferring ballast from Tank 10S to Tank 1P using the #2 ballast pump is valve __________.
In the event the motion of the DEEP DRILLER is such that critical motion limits are exceeded, you should __________.
When should the emergency position-indicating radio beacon be activated after abandoning a MODU?
Why are symmetric mooring patterns frequently used to keep MODU's on station?
The DEEP DRILLER is loaded as shown in the Sample Load Form #1 (Transit). Weather conditions require ballasting to survival draft. Assume that 4087 long tons of ballast are added at an average VCG of 8.32 feet. What would be the value of uncorrected KG?
If a MODU takes a sudden severe list or trim from an unknown cause, you should FIRST __________.
A semisubmersible at a draft of 19 feet 9 inches arrives on location planning to deploy eight mooring lines. Each anchor weighs 15 long tons and each mooring line consists of 3,000 feet of 3-inch chain (89.6 lbs/ft). If no ballast corrections are made, what is the expected draft if the average TPI is 60?
A semisubmersible, while floating level, displaces 20,000 long tons. LCB is 3.0 feet forward of amidships. Bulk, weighing 300 long tons, is placed in P-tanks located 40 feet aft of amidships. What is the new LCG?
Why can a person's sense of smell not be depended upon to detect H2S?
How must each storage tank for helicopter fuel on a MODU be marked?
The DEEP DRILLER is loaded as shown in Sample Load Form #4. While the unit is deballasting, port valve 5 fails in the closed position. You may deballast from tank 2P by pumping from tank 9P by also opening valves 6 and __________.
For a MODU with trim, an increase in GMT will cause the inclination to __________.
The DEEP DRILLER, at a draft of 60 feet, has VM of 942,120 ft-tons, and FSML of 36,235 ft-tons. What is the KGL?
The connection facilities for the international shore connection required on board offshore drilling units in international service must be located to provide access __________.
The DEEP DRILLER may remain at operating draft instead of deballasting to survival draft when __________.
An uncontrolled flow of gas, oil, or other well fluids into the atmosphere is called a __________.
The DEEP DRILLER is loaded as shown in the Sample Load Form #5 (Survival) when an unexpected slowly increasing port list and bow down trim occurs. A leak in C1P is found. By deballasting from ballast tanks 2P and 3P, the inclination slowly decreases. The increase in the transverse free surface correction is __________.
The discharge side of every fire pump must be equipped with a __________.
In a semisubmersible MODU, the columns contain void spaces above the waterline that are used principally for __________.
Which of the following will the certificate of inspection of a MODU specify?
Load line regulations are designed to ensure that a MODU has adequate structural strength and sufficient __________.
To determine the number of portable fire extinguishers required on a mobile offshore drilling unit, you should check the __________.
In the DEEP DRILLER, VCG is obtained from the sum of the vertical moments by __________.
A survival craft being used to pick up a person who has fallen overboard from a MODU should approach the person __________.
The end of the joint with the exterior threads is called the __________.
Laying down drill pipe from the derrick of a semisubmersible on location reduces the __________.
The prohibition against exceeding the load line draft may be considered temporarily not applicable when __________.
The two factors which make underwater hull repair of a MODU difficult are accessibility and the __________.
Survival practice in the mooring system is to slack off the tensions on the leeward side and __________.
While in ocean transit, the COASTAL DRILLER has a roll period of four seconds. What would be the largest angle each side of vertical that does not exceed the design limit of the legs?
Each person on the rig has a designated area to proceed to in the event of a fire. This assignment is shown clearly on which of the following documents?
The COASTAL DRILLER is loaded as shown in the Sample Load Form #1 (Rig Move). What is the new VCG if the entire contents of drill water tanks 6 and 7 are discharged?
If a severe storm threatens the COASTAL DRILLER while elevated as shown in the Sample Load Form #3 (Drilling), the variable loads would have to be reduced by __________.
The generators on your rig have shut down, leaving you without navigation lights. Which emergency signal would you transmit over the VHF radio to alert vessels in the area of your predicament?
The DEEP DRILLER, at 60.0 feet draft in sea water, discharges 275.8 long tons. What is the new draft?
If the DEEP DRILLER is damaged, the unit is designed to avoid downflooding in wind speeds up to __________.
The Cantilever Beam Load Chart for the COASTAL DRILLER shows the limits in the hook setback conductor tension, and __________.
What type of test determines the pressure at which the formation immediately below the last set casing will take fluid?
The size of fire hydrant hose connections on a cargo vessel must be either 1-1/2 inches or __________.