Able Seaman (AB) Exam — Questions and Answers

Question 1: Under the Navigation Rules, which of the following vessels has the highest priority and right-of-way over all other vessels?

A vessel constrained by her draft
A vessel not under command (Correct answer)
A sailing vessel underway
A vessel engaged in fishing

Correct answer: A vessel not under command

Rule 18 outlines the hierarchy of responsibility between vessels. A vessel not under command (NUC) is unable to maneuver as required by the rules and therefore cannot keep out of the way of other vessels. Consequently, all other vessels (including those fishing, sailing, or power-driven) must keep out of her way.

Question 2: The Emergency Fire Control Plan posted aboard a vessel shows:

Evacuation routes to lifeboats only
Location of fire-fighting equipment, fire zones, and detection systems (Correct answer)
Cargo manifest and stowage plan
Personal protective equipment stowage locations only

Correct answer: Location of fire-fighting equipment, fire zones, and detection systems

The fire control plan displays fire zones, locations of fire-fighting appliances, detection systems, and means of stopping ventilation and closing watertight doors.

Question 3: When donning a Self-Contained Breathing Apparatus (SCBA), the facepiece seal must be checked by:

Performing a positive and negative pressure test (Correct answer)
Spraying water on the mask
Observing the pressure gauge reads full
Asking a shipmate to inspect the straps

Correct answer: Performing a positive and negative pressure test

Positive and negative pressure seal checks confirm the facepiece is airtight before entering a hazardous atmosphere.

Question 4: What is a vessel's 'righting moment'?

The turning force applied by the rudder
The restoring force that returns a heeled vessel toward upright (Correct answer)
The holding force of the anchor and chain
The force causing a vessel to heel over

Correct answer: The restoring force that returns a heeled vessel toward upright

The righting moment is the couple acting to restore a heeled vessel to upright, equal to the vessel's displacement multiplied by the righting arm (GZ).

Question 5: While working on deck, a shipmate collapses and is not breathing. You are the first to respond. After ensuring the scene is safe, what is your immediate next action?

Call for help and check for a pulse. (Correct answer)
Roll the person into the recovery position.
Start chest compressions immediately.
Run to find the ship's medical officer.

Correct answer: Call for help and check for a pulse.

In any first aid scenario, the first step after ensuring your own safety is to assess the victim and summon assistance. You should loudly call for help to alert others who can assist and bring necessary medical equipment, while simultaneously checking for vital signs like a pulse to determine the next course of action (e.g., starting CPR).

Question 6: What happens to a vessel's initial stability when the center of gravity (G) rises?

The vessel trims by the head
Stability increases as GM grows
Stability decreases as GM is reduced (Correct answer)
Stability is unaffected by G position

Correct answer: Stability decreases as GM is reduced

As G rises, the distance between G and M (GM) decreases, reducing the vessel's initial stability and its resistance to rolling.

Question 7: Which agent is used in a foam fire extinguisher and works by forming a blanket over burning liquids?

Sodium bicarbonate
Aqueous Film-Forming Foam (AFFF) (Correct answer)
Carbon dioxide
Monoammonium phosphate

Correct answer: Aqueous Film-Forming Foam (AFFF)

AFFF creates a film over liquid fuel surfaces that prevents vapors from escaping and reaching ignition sources.

Question 8: What is the meaning of the term 'deviation' as used in compass adjustment?

The error of the magnetic compass caused by the ship's own magnetic fields (Correct answer)
The angular difference between the gyrocompass heading and the true heading
The difference between true north and magnetic north caused by the Earth's magnetic field
The angle between the vessel's course and the direction of leeway

Correct answer: The error of the magnetic compass caused by the ship's own magnetic fields

Deviation is the error in a magnetic compass caused by the vessel's own iron, steel, and electrical equipment — it changes with the ship's heading.

Question 9: A lookout is ordered to report a contact. The proper format for reporting a visual sighting is:

Relative bearing and description of the object (Correct answer)
True bearing, distance, and ship name if readable
Object name, color, and estimated size
Object type and time of sighting only

Correct answer: Relative bearing and description of the object

Lookouts report sightings using relative bearing (e.g., 'Red light, broad on the port bow') so the bridge team can immediately locate the contact.

Question 10: A 'heaving line' is used in mooring operations to:

Measure the depth of water at the berth
Secure the vessel to a mooring buoy
Pass anchoring instructions to dock workers
Haul a heavy mooring line across to the dock (Correct answer)

Correct answer: Haul a heavy mooring line across to the dock

A heaving line is a lightweight line thrown to the dock or another vessel to pull a heavier mooring hawser across the gap.

Question 11: When two power-driven vessels are in a crossing situation, which vessel must give way?

The vessel on the starboard side of the other
The vessel that is larger
The vessel traveling at higher speed
The vessel on the port side of the other (Correct answer)

Correct answer: The vessel on the port side of the other

Rule 15 states the vessel that has the other on her own starboard side shall keep out of the way; conversely, the vessel on the port side of the other gives way.

Question 12: When entering a potentially oxygen-deficient confined space onboard, what is required before entry?

Continuous ventilation, gas testing, and an attendant stationed outside with a rescue line (Correct answer)
A 15-minute waiting period after ventilating
A buddy system with two people entering simultaneously
A signed permit from the port authority

Correct answer: Continuous ventilation, gas testing, and an attendant stationed outside with a rescue line

Confined space entry requires continuous forced ventilation, atmospheric testing for oxygen and toxic gases, and a trained attendant outside ready to assist with rescue.

Question 13: What does a single red flare fired from a distress rocket indicate?

Man overboard on the port side
Distress and need of assistance (Correct answer)
The vessel is at anchor
A diver is below

Correct answer: Distress and need of assistance

A rocket throwing red stars or a red parachute flare is an internationally recognized distress signal indicating need of assistance.

Question 14: What term describes the cargo space below the main deck that is NOT a hold?

Forecastle
Tween-deck space
Deep tank (Correct answer)
Orlop deck

Correct answer: Deep tank

Deep tanks are enclosed spaces in the lower part of the ship used for liquid cargo or ballast, distinct from dry cargo holds.

Question 15: According to the International Regulations for Preventing Collisions at Sea, a vessel is considered to be 'underway' when she is:

Not at anchor, not made fast to shore, and not aground (Correct answer)
Steaming at more than 3 knots
Operating under engine power only
Moving through the water at any speed

Correct answer: Not at anchor, not made fast to shore, and not aground

COLREGS Rule 3 defines 'underway' as not at anchor, not made fast to shore, and not aground — regardless of whether the vessel is moving.

Question 16: What is the correct procedure if a crewmember's clothing catches fire?

Remove the clothing as quickly as possible
Run to the nearest fire station for assistance
Jump overboard to extinguish the flames
Stop, drop, and roll on the deck (Correct answer)

Correct answer: Stop, drop, and roll on the deck

Stop, drop, and roll smothers flames by cutting off airflow, and is the universally correct response to burning clothing.

Question 17: What does the term 'smothering' mean in fire suppression?

Chemically inhibiting the chain reaction
Removing the fuel source from the fire
Cutting off the oxygen supply to the fire (Correct answer)
Cooling the fire below ignition temperature

Correct answer: Cutting off the oxygen supply to the fire

Smothering extinguishes fire by excluding oxygen, one of the three elements of the fire triangle.

Question 18: What is the meaning of a black circle on the NFPA 704 hazard diamond (fire diamond)?

The material is water-reactive (Correct answer)
The material presents a cryogenic hazard
The material is radioactive
The material is an oxidizer

Correct answer: The material is water-reactive

A white square with a 'W' crossed out on the NFPA 704 diamond indicates the material reacts dangerously with water; a plain white section can indicate special hazard codes.

Question 19: What is the primary advantage of a 'double sheet bend' over a single sheet bend?

Faster to tie
Works better with lines of equal diameter
Greater security and resistance to slipping (Correct answer)
Easier to untie under load

Correct answer: Greater security and resistance to slipping

The double sheet bend adds an extra tuck, providing greater holding power especially in slippery or wet synthetic lines.

Question 20: Chafing gear is applied to a mooring line to:

Increase the line's breaking strength
Make the line easier to handle
Prevent the line from stretching
Protect it from wear where it passes over rough surfaces (Correct answer)

Correct answer: Protect it from wear where it passes over rough surfaces

Chafing gear such as canvas or rubber wrapping protects lines from abrasion at chock or fairlead contact points.

Question 21: When fighting a fire in a confined space, a firefighter's air supply in an SCBA typically lasts how long under heavy work conditions?

60 to 90 minutes
15 to 30 minutes (Correct answer)
5 to 10 minutes
45 to 60 minutes

Correct answer: 15 to 30 minutes

Under strenuous activity, a standard 30-minute SCBA cylinder is often depleted in 15–30 minutes due to increased breathing rate.

Question 22: Under MARPOL Annex V, which of the following types of garbage is strictly prohibited from being discharged into the sea at any time or location?

Dunnage and other floating packing materials
Food waste ground to less than 25mm
Cargo residues that are not harmful to the marine environment
Plastics, including synthetic ropes and fishing nets (Correct answer)

Correct answer: Plastics, including synthetic ropes and fishing nets

MARPOL Annex V establishes a general prohibition on the discharge of all garbage unless expressly allowed. Plastics, in any form, are completely banned from discharge anywhere at sea due to their persistence and severe harm to marine life. The other listed items may be discharged under specific conditions related to the ship's distance from land and whether it is in a designated 'Special Area'.

Question 23: Under COLREGS Rule 9, a vessel of less than 20 meters in length navigating in a narrow channel shall:

Proceed only during daylight hours without special permission
Always sound two short blasts before entering the channel
Not impede the passage of a vessel that can only safely navigate within the channel (Correct answer)
Anchor in the center of the channel and wait for traffic to clear

Correct answer: Not impede the passage of a vessel that can only safely navigate within the channel

Rule 9 requires small vessels (under 20 m) and sailing vessels not to impede the passage of vessels that can only safely navigate within a narrow channel.

Question 24: A white light visible all around at a range of two miles is displayed by which type of vessel?

A power-driven vessel over 50 meters
A vessel under 12 meters at anchor (Correct answer)
A vessel at anchor under 50 meters in length
A vessel not under command

Correct answer: A vessel under 12 meters at anchor

Rule 30 permits a vessel under 12 meters at anchor to show a single all-around white light instead of the forward and after anchor lights.

Question 25: What does a rapidly falling barometer indicate?

Clearing skies
Fair weather
Light winds
Approaching storm (Correct answer)

Correct answer: Approaching storm

A rapidly falling barometer indicates an approaching storm or rapidly deteriorating weather conditions.

Question 26: When using an EPIRB manually, what must the operator do to activate it?

Remove and replace the battery to trigger activation
Press the distress button three times
Submerge it in seawater
Remove the protective cap and extend the antenna, then switch to ON (Correct answer)

Correct answer: Remove the protective cap and extend the antenna, then switch to ON

Manual EPIRB activation requires removing the protective cap, extending the antenna, and switching the unit to the ON or MANUAL position.

Question 27: What is the purpose of the International Safety Management (ISM) Code?

To set maximum cargo weight limits
To establish manning requirements for all vessel types
To provide an international standard for safe ship management and pollution prevention (Correct answer)
To regulate crew wages on international voyages

Correct answer: To provide an international standard for safe ship management and pollution prevention

The ISM Code establishes an international standard for the safe management and operation of ships and pollution prevention.

Question 28: During a fire emergency, what is the primary purpose of boundary cooling?

To extinguish the fire directly
To cool fire-fighting personnel
To reduce smoke in passageways
To prevent fire from spreading to adjacent compartments (Correct answer)

Correct answer: To prevent fire from spreading to adjacent compartments

Boundary cooling involves applying water to bulkheads, decks, and doors surrounding a fire to prevent heat transfer and spread.

Question 29: Which type of synthetic fiber line has the greatest elasticity and is often used as a 'shock absorber' in mooring systems?

Nylon (Correct answer)
Polyester (Dacron)
Polypropylene
High-modulus polyethylene (HMPE)

Correct answer: Nylon

Nylon stretches up to 40% before breaking, making it ideal as a spring or shock-absorbing element in mooring arrangements.

Question 30: Which type of fire extinguisher is MOST appropriate for a Class B fire involving flammable liquids?

Wet chemical
Water (APW)
Soda-acid
CO2 or dry chemical (BC or ABC rated) (Correct answer)

Correct answer: CO2 or dry chemical (BC or ABC rated)

CO2 and dry chemical extinguishers rated for Class B fires are effective on flammable liquid fires such as fuel or oil.

Question 31: You are standing watch as part of the fire patrol. You discover a fire in a trash can in the ship's laundry. What is the FIRST action you should take?

Attempt to extinguish the fire with the nearest appropriate extinguisher.
Immediately evacuate the area and close the door behind you.
Use a fire hose to douse the entire compartment with water.
Sound the fire alarm and report the location of the fire. (Correct answer)

Correct answer: Sound the fire alarm and report the location of the fire.

The absolute first priority upon discovering a fire is to alert the crew. Sounding the alarm ensures a rapid, organized response from the entire ship's fire party and bridge team. Reporting the location allows responders to proceed directly to the scene with the correct equipment. Personal attempts to fight the fire should only begin after the alarm has been raised and if it is safe to do so.

Question 32: Under what condition should an AB refuse to carry out an order?

When the order would create an imminent danger to life or the vessel (Correct answer)
When the task is outside normal job duties
When the order comes from a junior officer
When the AB is tired from a previous watch

Correct answer: When the order would create an imminent danger to life or the vessel

An AB may and should refuse an order that would create an imminent and serious risk to their own safety, the safety of others, or the vessel.

Question 33: What effect does adding heavy deck cargo have on vessel stability?

Increases freeboard, improving overall safety
Has no effect on stability if the cargo is secured
Raises G and reduces GM, decreasing stability (Correct answer)
Lowers G and increases GM, improving stability

Correct answer: Raises G and reduces GM, decreasing stability

Adding weight high on deck raises the vessel's center of gravity G, reducing GM and decreasing initial stability.

Question 34: Under MARPOL Annex I, what is the maximum oil content permitted in bilge water discharged overboard outside special areas?

5 ppm
25 ppm
100 ppm
15 ppm (Correct answer)

Correct answer: 15 ppm

MARPOL Annex I requires that bilge water discharged outside special areas must not exceed 15 parts per million (ppm) oil content.

Question 35: Which of the following items is NOT typically required to be in a lifeboat's SOLAS 'A' Pack or a vessel's emergency grab bag?

First-aid kit and seasickness tablets.
Emergency food rations and drinking water.
Personal passports and crew documents. (Correct answer)
Flares and other signaling devices.

Correct answer: Personal passports and crew documents.

While personal documents are important, they are not a required item in a SOLAS-approved lifeboat survival kit or a standard emergency grab bag. The focus of these kits is on immediate survival: distress signaling (flares), medical treatment (first-aid kit), and sustenance (food/water).

Question 36: What is the MARPOL Annex I concerned with?

Prevention of pollution by sewage from ships
Prevention of pollution by oil from ships (Correct answer)
Prevention of pollution by noxious liquid substances
Prevention of air pollution from ships

Correct answer: Prevention of pollution by oil from ships

MARPOL Annex I covers regulations for the prevention of pollution by oil, including discharge standards and required equipment like ORBs.

Question 37: Which of the following is the correct definition of a 'bitter end'?

The end of the anchor chain secured inside the chain locker (Correct answer)
The section of line between two knots
The end of a line that is spliced to a shackle
The working end of a line in active use

Correct answer: The end of the anchor chain secured inside the chain locker

The bitter end is the inboard end of the anchor chain or a mooring line that is secured at the chain locker or vessel's fixed point.

Question 38: On a vessel with a conventional rudder, when the order 'hard right rudder' is given, the bow will initially swing to the right and the stern will:

Swing to the right (starboard) as well
Remain stationary due to forward momentum
Dip lower in the water due to increased resistance
Swing to the left (port) (Correct answer)

Correct answer: Swing to the left (port)

When the rudder is put hard right, the stern kicks to port (left) as the bow swings to starboard — the ship pivots about a point roughly one-third aft of the bow.

Question 39: A fellow crew member has collapsed after entering a recently opened ballast tank. As the first person on the scene, what is your most important immediate action?

Begin ventilating the space with a portable blower.
Activate the ship's general alarm and inform the bridge. (Correct answer)
Immediately enter the space to pull the crew member to safety.
Lower a breathing apparatus down to the collapsed crew member.

Correct answer: Activate the ship's general alarm and inform the bridge.

The crew member has likely succumbed to a hazardous atmosphere (oxygen deficiency or toxic gas). The primary rule of enclosed space rescue is to never enter without proper personal protective equipment (PPE) and a standby person, as you would likely become a second victim. The most critical first step is to raise the alarm to summon the trained and equipped rescue team and inform the ship's command.

Question 40: You are on a power-driven vessel and see a sailing vessel on your starboard bow on a collision course. According to the hierarchy of responsibilities between vessels (Rule 18), which vessel is the stand-on vessel?

The sailing vessel. (Correct answer)
The power-driven vessel because it is more maneuverable.
Whichever vessel is larger.
Both vessels are give-way and must take action.

Correct answer: The sailing vessel.

Rule 18 establishes a hierarchy of responsibility. A power-driven vessel underway shall keep out of the way of a sailing vessel, unless the sailing vessel is overtaking the power-driven vessel. Therefore, the sailing vessel is the stand-on vessel and should maintain its course and speed.

Question 41: Under the COLREGS, Rule 5 requires every vessel to maintain a proper lookout. Which of the following BEST describes this requirement?

A licensed officer must be on the bridge at all times
Radar watch substitutes for a physical lookout in clear weather
A lookout must be posted only in restricted visibility
Every vessel shall maintain a proper lookout by sight and hearing at all times (Correct answer)

Correct answer: Every vessel shall maintain a proper lookout by sight and hearing at all times

Rule 5 requires every vessel to maintain a proper lookout by sight and hearing, as well as all available means, at all times to make a full appraisal of the situation.

Question 42: Under the COLREGS, which vessel is the 'stand-on' vessel in a crossing situation between two power-driven vessels?

The larger vessel
The vessel with the other on her port side
The vessel with the other on her starboard side (Correct answer)
The faster vessel

Correct answer: The vessel with the other on her starboard side

In a crossing situation, the vessel that has the other vessel on her starboard side is the stand-on vessel and must maintain course and speed.

Question 43: A vessel's stability is compromised after flooding a compartment. What is the immediate corrective action to restore stability?

Counter-flood an opposite compartment to reduce listing and activate damage control pumps (Correct answer)
Jettison cargo from the bow
Move all crew to the high side of the vessel
Increase speed to generate dynamic lift

Correct answer: Counter-flood an opposite compartment to reduce listing and activate damage control pumps

Counter-flooding an opposite compartment can reduce a dangerous list, while damage control pumps work to remove water from the flooded space.

Question 44: What is the purpose of the 'Garbage Management Plan' required by MARPOL Annex V?

To track crew overtime during garbage handling
To estimate cargo weight for stability calculations
To provide written procedures for collecting, storing, and disposing of garbage (Correct answer)
To schedule port waste reception facility bookings

Correct answer: To provide written procedures for collecting, storing, and disposing of garbage

The Garbage Management Plan provides written procedures that all crew must follow for handling, storing, and disposing of ship-generated garbage.

Question 45: A 'breast line' used in mooring is a line that runs:

From the bow to the stern along the dock face
At a right angle from the vessel's side to the dock (Correct answer)
Diagonally forward from the bow to the dock
Aft from the stern at a 45-degree angle

Correct answer: At a right angle from the vessel's side to the dock

A breast line runs perpendicular (at 90 degrees) from the ship's side to the dock, preventing the vessel from moving away from the berth.

Question 46: What is the function of a 'pig' in pipeline or hose operations on a tanker?

A device pushed through piping to clean or inspect it (Correct answer)
A pressure relief fitting on cargo manifolds
A type of foam nozzle for fire fighting
A valve that controls cargo flow rate

Correct answer: A device pushed through piping to clean or inspect it

A pig is a device driven through a pipeline by pressure to clean, inspect, or separate products within the line.

Question 47: What does a hydrostatic release unit (HRU) on a liferaft do?

Transmits a distress signal to rescue services
Inflates the raft with CO2 when activated manually
Releases the raft from its cradle when a vessel sinks to 1.5-4 meters depth (Correct answer)
Keeps the raft attached to the vessel during bad weather

Correct answer: Releases the raft from its cradle when a vessel sinks to 1.5-4 meters depth

The HRU automatically releases the liferaft from its cradle when the vessel sinks to a depth of 1.5 to 4 meters.

Question 48: Under COLREGS, what is the difference between a 'short blast' and a 'prolonged blast'?

Short = 2 sec; Prolonged = 6–8 sec
Short = 1 sec; Prolonged = 4–6 sec (Correct answer)
Short = less than 1 sec; Prolonged = 3–5 sec
Short = 1 sec; Prolonged = 10 sec

Correct answer: Short = 1 sec; Prolonged = 4–6 sec

Rule 32 defines a short blast as about one second duration and a prolonged blast as from four to six seconds duration.

Question 49: Under the STCW Code, what is the minimum rest period required for watchkeepers to prevent fatigue-related accidents?

6 hours rest in any 24-hour period
8 hours rest in any 24-hour period
12 hours rest in any 24-hour period
10 hours rest in any 24-hour period (Correct answer)

Correct answer: 10 hours rest in any 24-hour period

STCW requires a minimum of 10 hours of rest in any 24-hour period and 77 hours in any 7-day period to prevent fatigue.

Question 50: What does a yellow over white light indicate?

Fishing at night
Under repair
Towing vessel (Correct answer)
Anchor light

Correct answer: Towing vessel

Under COLREGs Rule 24, a vessel engaged in towing, when the length of the tow exceeds 200 meters, must display a yellow all-around light above a white all-around light at the stern. This specific light combination serves as a clear signal to other vessels, indicating that it is a towing vessel with a long tow and requires extra caution.

Question 51: What is the primary purpose of plotting a running fix when only one landmark is available?

To correct for leeway and current simultaneously
To verify the accuracy of the GPS position
To obtain a position using two bearings of the same object taken at different times (Correct answer)
To determine the vessel's speed made good over the ground

Correct answer: To obtain a position using two bearings of the same object taken at different times

A running fix advances an earlier bearing line along the vessel's track to cross a new bearing of the same object, yielding a position with a single landmark.

Question 52: A 25-meter power-driven vessel, when underway at night, must exhibit which of the following lights as a minimum?

A masthead light forward, sidelights, and a sternlight. (Correct answer)
Sidelights and a sternlight only.
A masthead light forward, a second masthead light aft and higher, sidelights, and a sternlight.
One all-round white light and sidelights.

Correct answer: A masthead light forward, sidelights, and a sternlight.

Rule 23 states that a power-driven vessel underway shall exhibit a masthead light forward, sidelights (a green one on the starboard side and a red one on the port side), and a sternlight. A second masthead light abaft of and higher than the forward one is only required for vessels 50 meters or more in length.

Able Seaman (AB) Exam

The Able Seaman (AB) exam certifies mariners to perform duties as an Able Seaman on various vessels, demonstrating knowledge of seamanship, safety, and navigation.

Questions

60 min

Time Limit

70%

To Pass

Checking for saved progress...

Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds