COLREGs Lights & Shapes Practice Test

These questions are part of the practice quiz. Start practicing

• Which vessel type is NOT required to show masthead lights?
• What lights and shapes indicate the obstructed side of a vessel engaged in dredging or underwater operations?
• When a power-driven vessel is towing and the tow exceeds 200 metres, how is the masthead light displayed?
• When there is sufficient sea room, what is the most effective action to avoid a collision?
• What must a 50-meter power-driven vessel display at night?
• What type of light is used primarily for vessel signaling during the day?
• What does the term 'vessel constrained by her draft' refer to?
• What vessels may show an all-around red over an all-around green light?
• How many masthead lights must a 50-meter power-driven vessel exhibit?
• Which type of vessel exhibits an all-round green light over an all-round white light?
• When lights for restricted ability to maneuver are installed, what is the minimum distance they must be placed off the center line?
• What type of light should a vessel that is fishing but not trawling display?
• What optional lights may a sailing vessel display?
• When must the rules regarding shapes be adhered to?
• What additional signal is exhibited by an air cushion vessel operating in non-displacement mode?
• What does a towing light indicate?
• What configuration of lights is displayed by a vessel towing a vessel alongside?
• What action should a sailing vessel take when another sailing vessel approaches with the wind on its starboard side?
• On a vessel of 20 meters or more, what is the spacing between black balls?
• What type of vessel may combine her sidelights and stern light in a single lantern?
• When may a departure from the navigation rules be necessary?
• What is the exception to the requirement to show lights from sunset to sunrise?
• What lights are shown by a pilot vessel when not on pilotage duty?
• What does a diamond shape indicate for a dredging vessel?
• Where should a 'special flashing light' be mounted on a vessel in the Great Lakes Basin?
• When must the Rules concerning lights be complied with?
• When does a pilot vessel exhibit her identity lights?
• What lights does a composite unit exhibit?
• What is the required height of the after masthead light?
• What light(s) is fixed to show a light 67.5 degrees from right aft on each side of the vessel?
• What lights must a 50-meter power-driven vessel have when pushing a 210-meter group of barges?
• What is the required range of masthead lights on a vessel of 50 meters or more?
• What is the height of the masthead light of a power-driven vessel of 12 but less than 20 metres?
• On a power-driven vessel of 20 meters or more, where should sidelights be positioned?
• From when must the Rules concerning lights be complied with?
• Which vessel has the right of way when a power-driven vessel encounters a sailing vessel?
• What does a vessel under sail but also being propelled by machinery exhibit?
• What lights should a sailing vessel under 20 meters exhibit?
• What is the light character of an 'ODAS'?
• If you see only a green light over a white light and sidelights, what type of vessel is this?
• What is the minimum height for the masthead light on a high-speed craft?
• In the case of a tanker and a sailing vessel crossing ahead from starboard, which is the give-way vessel?
• What is indicated by three balls displayed in a vertical line?
• What do three all-around lights in a vertical line indicate?
• What kind of light must be exhibited by a WIG craft in flight near the surface?
• What type of vessels may use an all-round white light instead of separate masthead and stern lights?
• What is the visibility range of a masthead light?
• When shall the white flashing lights on an oil rig be exhibited?
• Which vessels show only sidelights and a sternlight?
• What lights would be visible from ahead of a 40-meter tug pushing two barges ahead?
• What type of vessel shall show no stern light but exhibit two yellow lights in a vertical line?
• What do two yellow lights in a vertical line indicate for a vessel?
• At what height shall the white flashing lights on an oil rig be placed?
• What light configuration indicates a vessel at anchor?
• How much higher must the after masthead light be compared to the forward masthead light on a power-driven vessel?
• Which white light is positioned over the fore and aft centerline of a vessel, showing an unbroken light over 225 degrees of the horizon?
• What characteristic is associated with a masthead light?
• When is a special flashing light exhibited?
• Which shape indicates a vessel is restricted in its ability to maneuver?
• How does a flashing light operate under the rules?
• What must WIG craft exhibit when not in flight?
• If a sailing vessel is also using propelling machinery, what lights must it exhibit?
• What is the minimum range of a stern light on a vessel that is 50 meters or more?
• Where should sidelights be placed on a vessel of 20 meters?
• What is indicated by a red light over a white light and another white light at a lower side level?
• What does three black balls in a vertical line signify?
• What is the arc of a 'special flashing light'?
• In what case can the lights on an oil rig be displayed outside the normal requirements?
• What special lights may a vessel engaged in purse seining display?
• What is the minimum length for a power-driven vessel to be required to exhibit two masthead lights?
• What is the term for a vessel being pushed and the pushing vessel when they are rigidly connected?
• What is the minimum range of a stern light on vessels less than 50 metres?
• What is the nominal range of the white flashing lights on an oil rig?
• Which light configuration indicates that a sailing vessel is operating machinery?
• What is the flash character and range of a blue flashing light?
• What lights may a sailing vessel underway exhibit?
• How is a risk of collision determined according to navigation rules?
• What vessels may exhibit a 'blue flashing light'?
• What does a sailing vessel of less than 20 meters combine regarding navigation lights?
• What is the minimum height above water for all-round white lights on an inconspicuous partly submerged object?
• What action should smaller vessels take in a narrow channel when larger vessels are present?
• How many all-round white lights are required for an inconspicuous partly submerged object?
• What shapes are exhibited by a vessel dredging and having an obstruction to port?
• What lights are exhibited by a vessel engaged in a towing operation that severely restricts its ability to deviate from its course?
• What lights must a vessel engaged in fishing at anchor display?
• According to maritime rules, which vessel is considered a stand-on vessel in a crossing situation?
• What does the term "flashing light" refer to?
• What is the key requirement for the placement of sidelights on a vessel of 20 meters or more in length?
• What type of sailing vessels can combine the side and stern lights in a single lantern?
• What action must a vessel take when it hears another's fog signal forward of its beam in thick fog?
• How should vessels being towed or pushed be illuminated according to maritime rules?
• What lights would be visible from astern of a 40-meter tug that is pushing two barges ahead?
• What constitutes a "flashing light" according to maritime regulations?
• How many masthead lights are required when a 50-meter power-driven vessel is towing a tow that exceeds 200 meters?
• What is the minimum range of a sidelight on a vessel that is less than 12 metres?
• At what height should a lantern be positioned for a sailing vessel under 20 meters?
• When is a vessel allowed to show an all-round light instead of a masthead and stern light?
• How many masthead lights must a 50-meter vessel display?
• What is the diameter of a black cone used on vessels?
• When is a diamond shape required to be displayed on a towing vessel?
• What is the minimum range of a masthead light for vessels ranging from 12 to less than 20 meters?
• What is the purpose of exhibiting lights for a towed object?
• What is the minimum range of the masthead light on vessels that are 50 meters or more in length?
• Under what conditions may lights be exhibited beyond sunset to sunrise?
• What is the minimum range of a masthead light on a vessel that measures 15 meters?
• Is a vessel allowed to engage in fishing within a traffic separation scheme?
• What signal should a vessel intend to overtake to port use?
• What lights are exhibited by a vessel recovering a helicopter while making way?
• What is the maximum height allowed for the masthead light on a vessel?
• What is indicated when a vessel only exhibits three all-round lights: upper red, lower red, and middle white?
• Which type of vessel may not impede another vessel navigating in a narrow channel?
• Which type of light signals that a vessel is being towed?
• What is the arc of visibility for a masthead light on a 75 metre vessel?
• What do the rules regarding lights apply to?
• What color is a 'special flashing light'?
• During a nighttime navigation, what additional light may a tug under 50 meters show while pushing?
• When is a diamond shape required on a towed vessel?
• Where is an after masthead light positioned on a vessel?
• In cases of restricted ability to maneuver, where should the lights be positioned?
• When power-driven vessels meet in a narrow channel with a tidal stream, which vessel is the stand-on vessel?
• What is the distance requirement for spacing between lights on a towing light?
• When two sailing vessels are approaching each other with the wind on opposite sides, which vessel is obligated to give way?
• What is the minimum height requirement for the forward masthead light on a power-driven vessel in the Great Lakes?
• What type of light is required for a vessel less than 7 metres in length?
• What should be avoided when determining the risk of collision?
• What is the minimum horizontal distance between two masthead lights on a power-driven vessel?
• What does the term 'close-quarters situation' refer to?
• What does a combination of two vertically disposed red lights and a lower white light indicate?
• Where should the lantern be placed on a sailing vessel displaying lights in a single lantern?
• What vessels show two red lights as well as anchor lights?
• What additional light must be displayed by an air cushion vessel in non-displacement mode?
• What is the arc coverage of a side light?
• What defines a 'special flashing light' in maritime rules?
• What is the maximum horizontal distance allowed between two masthead lights on a power-driven vessel?
• What signal indicates disagreement to being overtaken in a narrow channel?
• What additional light must WIG craft display in specific situations?
• What lights or shapes are required for a vessel under 12 metres when aground?
• What is the minimum range of a 'special flashing light'?
• When must a pilot boat exhibit a masthead light?
• Which light is characterized as yellow and has the same attributes as a sternlight?
• When may an anchored vessel of less than 7 metres dispense with showing any anchor lights?
• Which lights must a barge being towed exhibit according to international rules?
• What lights are exhibited by an inconspicuous, partly submerged vessel or object being towed?
• Which lights should be exhibited by a sailing vessel?
• What lights are shown by a vessel underway and engaged on pilotage duty?
• What lights are shown by a pushing vessel and a vessel being pushed when connected in a composite unit?
• When towing, how many masthead lights must a 50-meter power-driven vessel exhibit if the tow does not exceed 200 meters?
• What is the vertical spacing of lights indicating a trawler is shooting, hauling, or hung up?
• What signal indicates a vessel's agreement to being overtaken in a narrow channel?
• Which vessel shall operate white flashing lights flashing the Morse letter 'U'?
• What is the height restriction for foremast head light on vessels wider than 5 meters?
• Which lights are mandatory for a vessel recovering a helicopter at night?
• What lights are exhibited by a group of vessels being towed alongside or pushed ahead?
• What configuration indicates that a vessel is not making way?
• What is the height requirement for sidelights on a power-driven vessel?
• Which vessels display two towing lights in vertical alignment?
• What color is a towing light?
• Which vessels may exhibit a rigid replica of flag 'Alpha'?
• For a vessel less than 20 meters in length, where should the masthead light be exhibited?
• On a power-driven vessel of 20 meters or more in the Great Lakes, how far aft can the foremasthead light be placed?
• Which of the following lights must a vessel exert when at anchor?
• What is a key consideration when navigating in a narrow channel?
• What shape does a vessel proceeding under sail and propelled by machinery display?
• Which lights must a sailing vessel underway display?
• What is a primary characteristic of a maneuvering light on a vessel?
• What type of signal is typically displayed by a fishing vessel when engaged in fishing?
• What shapes are shown by a vessel aground?
• What is the horizontal separation required between obstruction lights and RAM lights on a dredge?
• Where is a 'special flashing light' typically placed on a vessel?
• When do the rules concerning lights need to be followed?
• In a towed alongside situation, what lights must be displayed?
• What light is exhibited by a WIG craft when taking off, landing, or in flight near the surface?
• What does 1 black ball indicate?
• What is the arc of a towing light?
• What factor is generally considered when defining a 'safe speed' for vessels?
• What is the minimum spacing between lights on a vessel of 20 metres in length or more in the Great Lakes Basin?
• What is the vertical spacing of the all-around white light for fishing gear over 150 meters?
• What is the purpose of the identity lights on a pilot vessel?
• What does the diamond shape signify when displayed by an object being towed?
• What is the primary rule regarding vessels navigating in traffic separation schemes?
• What does a side light indicate about a vessel?
• Where should the forward masthead light be placed on a power-driven vessel?
• If a vessel displaying a blue flashing light is approaching from astern, what should you do?
• What light must a WIG craft exhibit when taking off, landing, and flying near the surface?
• When can a vessel display a single all-round light at the top of the mast?
• If a power-driven vessel is less than 12 meters, what may it display instead of a masthead and stern light?
• What lights are required for an 8 metre vessel engaged in diving operations?
• What is meant by the term 'seaplane' in the rules?
• What type of light configuration does a towing vessel engaged in a towing operation necessitate?
• What must a vessel do if it cannot maintain its speed due to fog?
• What anchor shape or lights are shown by a vessel engaged in dredging?
• What is the minimum range of a masthead light on a vessel that is 50 meters or more in length?
• Which vessels are required to display masthead lights?
• What is the purpose of showing shapes and lights on vessels?
• What shape indicates that an object being towed is longer than 200 meters?
• When must a pilot boat exhibit sidelights and a stern light?
• Why should scanty information be approached with caution in navigation?
• What is the main reason for altering a course to avoid a close-quarters situation?
• In the context of the rules, what does the term 'mile' refer to?
• Which light configuration is displayed by a vessel that is restricted in its ability to maneuver?
• What is meant by an 'alternate system of navigation lights'?
• If an inconspicuous partly submerged object measuring 20m wide and 80m long is being towed, what lights are required?
• How is the intensity of a flashing light defined?
• What is the minimum range of all-round lights on vessels under 12 meters?
• Where should a single masthead light be placed on a power-driven vessel?
• In a narrow channel, which vessel must keep clear when a sailing vessel and a fishing vessel are approaching?
• Which of the following vessels may combine sidelights and stern light into a single lantern?
• What determines the positioning of the foremasthead light on a vessel?
• What distinguishes a special flashing light?
• What signal is made when approaching a bend or obstruction in a channel which may obscure another vessel?
• What light indicates that a vessel is being towed along with a composite unit?
• What does two vertically disposed red lights without other lights indicate?
• What should a vessel do if it is involved in a situation that requires a departure from the rules?
• What is the minimum height for the lowest light on a vessel of 20 metres in length in the Great Lakes?
• What is indicated by a vessel displaying 2 black balls in a vertical line?
• What is the required height above the hull of a masthead light on a vessel of 20 metres or more?
• Where is a towing light typically mounted?
• What is the term for a pushing vessel and a pushed barge that are rigidly connected?
• If a tug is towing three barges and is overtaken by a vessel under sail from dead astern, which vessel must give way?
• What vessel exhibits an all-round white light forward and aft?
• What does a sound signal of one prolonged followed by two short blasts indicate for a vessel seining or trawling?
• Which of the following lights must a dredging vessel display?