Navigation lights and day shapes practice test

Questions and answers

1. 1.The day shape for a vessel constrained by draught is:

   A.A ballB.A diamondC.A cylinderD.Two cones point to point
   Show answer

   Correct answer: C. A cylinder

   Rule 28: the day shape is a cylinder.

   Study Rule 28: Vessels Constrained by Their Draught

2. 2.Where it is impracticable for a seaplane or WIG craft to show the lights and shapes prescribed in Part C, she must:

   A.Exhibit only her aviation navigation lights, because Part C does not apply to aircraftB.Exhibit lights and shapes as closely similar as possible in characteristics and position to those prescribedC.Exhibit the lights and shapes of a power-driven vessel of less than 12 metres in length, whatever her actual sizeD.Exhibit an all-round flashing yellow light, like an air-cushion vessel in non-displacement mode
   Show answer

   Correct answer: B. Exhibit lights and shapes as closely similar as possible in characteristics and position to those prescribed

   Rule 31: where compliance is impracticable, seaplanes and WIG craft shall exhibit lights and shapes as closely similar in characteristics and position as possible.

   Study Rule 31: Seaplanes

3. 3.The day shape for a vessel engaged in fishing is:

   A.Two cones base to baseB.One cone, point downwardsC.Two cones point to pointD.A cylinder
   Show answer

   Correct answer: C. Two cones point to point

   Rule 26: fishing vessels display two cones point to point in a vertical line as a day shape.

   Study Rule 26: Fishing Vessels

4. 4.A vessel of 12 metres or more aground at night additionally shows:

   A.Two green all-round lights verticallyB.Three red all-round lights verticallyC.Two red all-round lights verticallyD.One red all-round light
   Show answer

   Correct answer: C. Two red all-round lights vertically

   Rule 30(d): a vessel aground shows anchor lights plus two all-round red lights in a vertical line.

   Study Rule 30: Anchored Vessels and Vessels Aground

5. 5.A vessel engaged in trawling shows:

   A.Red over white all-round lightsB.Green over white all-round lightsC.Two red all-round lightsD.White over red all-round lights
   Show answer

   Correct answer: B. Green over white all-round lights

   Rule 26(b)(i) prescribes green over white all-round lights for a vessel engaged in trawling; the fishing signals also apply while engaged in fishing at anchor.

   Study Rule 26: Fishing Vessels

6. 6.A vessel engaged in fishing with gear restricting manoeuvrability shows sidelights and a sternlight when:

   A.At anchorB.The sun has setC.Making way through the waterD.In a traffic separation scheme
   Show answer

   Correct answer: C. Making way through the water

   Rule 26: sidelights and sternlight are shown by fishing vessels only when making way through the water.

   Study Rule 26: Fishing Vessels

7. 7.A pilot vessel on duty displays at the masthead:

   A.Red over green all-round lightsB.White over red all-round lightsC.Two white all-round lightsD.Green over white all-round lights
   Show answer

   Correct answer: B. White over red all-round lights

   Rule 29(a): white over red all-round lights at or near the masthead.

   Study Rule 29: Pilot Vessels

8. 8.The day shape for a vessel of 12 metres or more aground is:

   A.One ballB.Two balls verticallyC.Three balls verticallyD.Ball, diamond, ball vertically
   Show answer

   Correct answer: C. Three balls vertically

   Rule 30(d): three balls in a vertical line is the day shape for a vessel aground.

   Study Rule 30: Anchored Vessels and Vessels Aground

9. 9.The day shape for a power-driven vessel towing astern when the tow exceeds 200 metres is:

   A.A coneB.A cylinderC.A diamond shapeD.Two cones point to point
   Show answer

   Correct answer: C. A diamond shape

   Rule 24(a)(v): a diamond shape is shown where it can best be seen if the tow exceeds 200 metres, measured from the stern of the towing vessel to the after end of the tow.

   Study Rule 24: Towing and Pushing

10. 10.A vessel constrained by her draught may display:

    A.Two red all-round lights verticallyB.Three red all-round lights verticallyC.A single all-round blue lightD.Red-white-red all-round lights
    Show answer

    Correct answer: B. Three red all-round lights vertically

    Rule 28: three red all-round lights vertically, in addition to normal power-driven vessel lights.

    Study Rule 28: Vessels Constrained by Their Draught

11. 11.A power-driven vessel towing astern with tow length exceeding 200 metres, measured from her stern to the after end of the tow, shows:

    A.Two masthead lights in a vertical lineB.Three masthead lights in a horizontal lineC.Three masthead lights in a vertical lineD.Four masthead lights in a vertical line
    Show answer

    Correct answer: C. Three masthead lights in a vertical line

    Rule 24(a)(i): three masthead lights in a vertical line when the tow exceeds 200 metres.

    Study Rule 24: Towing and Pushing

12. 12.For a vessel of 50m or more, the masthead light must be visible at:

    A.3 nautical milesB.5 nautical milesC.6 nautical milesD.8 nautical miles
    Show answer

    Correct answer: C. 6 nautical miles

    Rule 22: masthead light of vessels 50m+ must be visible at a minimum of 6 nautical miles.

    Study Rule 22: Visibility of Lights

13. 13.Identify the vessel from her navigation lights:

    A.Vessel constrained by draught — one masthead light shown (option for vessels <50 m); optional red lights and cylinder shown (Rule 28)B.Trawler not making way through the water — masthead light abaft and above the green light (required at ≥50 m; permitted below 50 m)C.Trawler making way through the water — masthead light abaft and above the green light (required at ≥50 m; permitted below 50 m)D.Power-driven vessel — two masthead lights shown (required at ≥50 m; also permitted below 50 m)
    Show answer

    Correct answer: A. Vessel constrained by draught — one masthead light shown (option for vessels <50 m); optional red lights and cylinder shown (Rule 28)

    Among the listed options, this display corresponds to: Vessel constrained by draught — one masthead light shown (option for vessels <50 m); optional red lights and cylinder shown (Rule 28). Viewing aspect: starboard side.

    Study Rule 28: Vessels Constrained by Their Draught

14. 14.A dredger of at least 12 metres restricted in ability to manoeuvre shows on the obstructed side:

    A.Two green all-round lights or diamondsB.Two red all-round lights or ballsC.A single yellow flashing lightD.Three white all-round lights
    Show answer

    Correct answer: B. Two red all-round lights or balls

    Rule 27(d): two red all-round lights or two balls on the obstructed side, two green or two diamonds on the clear side.

    Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre

15. 15.The second masthead light on a power-driven vessel must be:

    A.Abaft of and at the same height as the forward oneB.Lower than the forward oneC.Abaft of and higher than the forward oneD.Directly above the forward one, on the same mast
    Show answer

    Correct answer: C. Abaft of and higher than the forward one

    Rule 23(a)(ii): the second masthead light must be abaft of and higher than the forward one.

    Study Rule 23: Power-driven Vessels Underway

16. 16.Navigation lights must be displayed:

    A.From sunset to sunrise, and by day only when anchored in or near a fairwayB.From sunset to sunrise and, if carried, also by day in restricted visibilityC.From one hour before sunset until one hour after sunrise, whatever the visibilityD.Only when other vessels are nearby, by day or by night
    Show answer

    Correct answer: B. From sunset to sunrise and, if carried, also by day in restricted visibility

    Rule 20(b) requires prescribed lights from sunset to sunrise. Under 20(c), those lights, if carried, must also be shown by day in restricted visibility and may be shown in other circumstances when deemed necessary.

    Study Rule 20: Application (Lights)

17. 17.A vessel of at least 12 metres not under command (NUC) shows which status lights?

    A.Two all-round green lights verticallyB.Two all-round red lights verticallyC.Three all-round red lights verticallyD.Red over white over red all-round lights
    Show answer

    Correct answer: B. Two all-round red lights vertically

    Rule 27(a)(i) prescribes two all-round red lights vertically. Under Rule 27(g), vessels under 12 metres, except those engaged in diving operations, are not required to show the Rule 27 lights and shapes.

    Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre

18. 18.A vessel of 50 metres or more at anchor at night shows:

    A.Two all-round red lights in a vertical lineB.An all-round white light forward and a lower one aftC.An all-round white light aft and a lower one forwardD.A single all-round white light where it can best be seen
    Show answer

    Correct answer: B. An all-round white light forward and a lower one aft

    Rule 30(a): an all-round white light in the fore part and another all-round white light at a lower level near the stern.

    Study Rule 30: Anchored Vessels and Vessels Aground

19. 19.Identify the vessel from her navigation lights:

    A.Vessel aground — two anchor lights shown (required at ≥50 m; permitted below 50 m)B.Vessel aground — one anchor light shown (alternative below 50 m)C.Vessel at anchor — one anchor light shown (alternative below 50 m)D.Vessel at anchor — two anchor lights shown (required at ≥50 m; permitted below 50 m)
    Show answer

    Correct answer: D. Vessel at anchor — two anchor lights shown (required at ≥50 m; permitted below 50 m)

    Among the listed options, this display corresponds to: Vessel at anchor — two anchor lights shown (required at ≥50 m; permitted below 50 m). Viewing aspect: stern.

    Study Rule 30: Anchored Vessels and Vessels Aground

20. 20.Identify the vessel from her navigation lights:

    A.Vessel restricted in ability to manoeuvre, not making way through the waterB.Power-driven vessel < 12 m — simplifiedC.Pilot vessel underway; engaged on pilotage dutyD.Sail only → main option: 3 separate lights
    Show answer

    Correct answer: B. Power-driven vessel < 12 m — simplified

    Among the listed options, this display corresponds to: Power-driven vessel < 12 m — simplified. Viewing aspect: starboard side.

    Study Rule 23: Power-driven Vessels Underway

21. 21.From which aspect are you observing this vessel?

    A.Starboard aspectB.Stern aspectC.Bow aspectD.Port aspect
    Show answer

    Correct answer: A. Starboard aspect

    Vessel: Tug <50 m — tow >200 m. Viewing aspect: starboard side. The other listed aspects show different combinations of lights.

    Study Rule 24: Towing and Pushing

22. 22.The towing light is:

    A.White, with the same arc as the sternlightB.Yellow, with the same arc as the masthead lightC.Yellow, with the same arc as the sternlightD.Yellow and flashing, visible all round the horizon
    Show answer

    Correct answer: C. Yellow, with the same arc as the sternlight

    Rule 21(d) defines the towing light as yellow with the same characteristics as the sternlight. Rule 24(a)(iv) places it in a vertical line above the sternlight.

    Study Rule 24: Towing and Pushing

23. 23.A masthead light shows over an arc of:

    A.135 degreesB.180 degreesC.225 degreesD.360 degrees
    Show answer

    Correct answer: C. 225 degrees

    Rule 21(a): masthead light shows over an arc of 225 degrees from dead ahead to 22.5 degrees abaft the beam on each side.

    Study Rule 21: Definitions (Lights)

24. 24.Under the normal arrangement in Rule 23(a), a power-driven vessel of 50 metres or more underway must show:

    A.One masthead light, sidelights, and sternlightB.Two masthead lights, sidelights, and sternlightC.Three masthead lights, sidelights, and sternlightD.Two masthead lights and sidelights, but no sternlight
    Show answer

    Correct answer: B. Two masthead lights, sidelights, and sternlight

    Rule 23(a): vessels 50m+ must show two masthead lights (forward and aft), sidelights, and sternlight.

    Study Rule 23: Power-driven Vessels Underway

25. 25.Identify the vessel from her navigation lights:

    A.Vessel not under command, not making way through the waterB.Tug <50 m — tow >200 mC.Vessel not under command, making way through the waterD.Tug <50 m — tow ≤200 m
    Show answer

    Correct answer: C. Vessel not under command, making way through the water

    Among the listed options, this display corresponds to: Vessel not under command, making way through the water. Viewing aspect: starboard side.

    Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre

26. 26.Under the standard arrangement in Rule 25(a), a sailing vessel underway displays which navigation lights?

    A.A masthead light, sidelights and a sternlightB.Sidelights and a sternlightC.An all-round white light onlyD.Sidelights only
    Show answer

    Correct answer: B. Sidelights and a sternlight

    Rule 25(a) prescribes sidelights and a sternlight for a sailing vessel underway. Rule 25(b) permits a combined lantern below 20 m; paragraph (c) allows a separate red-over-green pair, not with that combined lantern; paragraph (d) provides a conditional alternative below 7 m.

    Study Rule 25: Sailing Vessels Underway and Vessels Under Oars

27. 27.A vessel under oars at night, if she does not exhibit the lights for sailing vessels, shall:

    A.Exhibit a masthead light, sidelights and a sternlight, exactly like a power-driven vessel of her lengthB.Exhibit an all-round flashing yellow light from sunset to sunrise while under oarsC.Have ready an electric torch or lantern showing a white light, to exhibit in time to prevent collisionD.Show no lights, as vessels under oars are exempt from the lights and shapes of Part C
    Show answer

    Correct answer: C. Have ready an electric torch or lantern showing a white light, to exhibit in time to prevent collision

    Rule 25(d): a vessel under oars may exhibit the lights prescribed for sailing vessels; if she does not, she shall have ready at hand an electric torch or lighted lantern showing a white light to be exhibited in sufficient time to prevent collision.

    Study Rule 25: Sailing Vessels Underway and Vessels Under Oars

28. 28.The optional pair of all-round lights near the top of a sailing vessel's mast is:

    A.White over redB.Red over greenC.Green over whiteD.Two white lights
    Show answer

    Correct answer: B. Red over green

    Rule 25(c) permits red over green all-round lights, in addition to separate sidelights and sternlight. These are not masthead lights as defined in Rule 21(a), and must not be combined with the Rule 25(b) combined lantern.

    Study Rule 25: Sailing Vessels Underway and Vessels Under Oars

29. 29.An air-cushion vessel operating in non-displacement mode must additionally show:

    A.Two all-round red lights in a vertical lineB.An all-round flashing yellow lightC.An all-round flashing blue lightD.Three masthead lights in a vertical line
    Show answer

    Correct answer: B. An all-round flashing yellow light

    Rule 23(b): an air-cushion vessel in non-displacement mode shows an all-round flashing yellow light.

    Study Rule 23: Power-driven Vessels Underway

30. 30.A vessel of at least 12 metres restricted in her ability to manoeuvre, other than one engaged in mineclearance, displays which status lights?

    A.Two red all-round lights verticallyB.Red-white-red all-round lights verticallyC.Green-white-green all-round lights verticallyD.Three red all-round lights vertically
    Show answer

    Correct answer: B. Red-white-red all-round lights vertically

    Rule 27(b): RAM shows three all-round lights — red, white, red (top to bottom).

    Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre

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Read the rules behind the questions

• Study Rule 23: Power-driven Vessels Underway
• Study Rule 26: Fishing Vessels
• Study Rule 27: Vessels Not Under Command or Restricted in Ability to Manoeuvre
• Study Rule 30: Anchored Vessels and Vessels Aground