Question 1 of 10
At night you see these lights. What is it?
Correct!Not quite. The answer is Power-driven vessel, 50 m or more.
Two masthead lights (the aft one higher), sidelights and a sternlight. You are on her port bow. Rule 23(a)
Navigation lights and day shapes quiz
Ten questions on COLREG Rules 21 to 31. Look at the lights or shapes, pick an answer, and the rule behind it appears.
10 questions · answers explained · no sign-up
Question 2 of 10
At night: which picture shows a vessel engaged in trawling?
Correct!Not quite. The answer is Vessel engaged in trawling (not making way).
All-round green over white. Sidelights and sternlight only when making way. By day two cones, points together. In the right picture you are right ahead of her. Rule 26(b)
Question 3 of 10
By day you see this. What is it?
Correct!Not quite. The answer is Vessel at anchor.
All-round white light(s): two if 50 m or more (the forward one higher), one if less than 50 m. By day one ball. You are right ahead of her. She is 50 m or more. Rule 30(a)
Question 4 of 10
At night you see these lights. What is it?
Correct!Not quite. The answer is Vessel constrained by her draught.
The lights of a power-driven vessel plus three all-round red lights in a vertical line. By day a cylinder. You are on her starboard bow. Rule 28
Question 5 of 10
At night you see these lights. What is it?
Correct!Not quite. The answer is Power-driven vessel towing, tow 200 m or less.
Two masthead lights in a vertical line, sidelights, sternlight and a yellow towing light above the sternlight. You are on her port beam. She is towing astern. Rule 24(a)
Question 6 of 10
At night you see these lights. What is it?
Correct!Not quite. The answer is Sailing vessel underway.
Sidelights and a sternlight only. Under 20 m they may be combined in one tricolour lantern at the top of the mast. She may also show all-round red over green at the top of the mast (never with the tricolour). You are on her starboard beam. She is underway, with optional red over green. Rule 25
Question 7 of 10
By day you see this. What is it?
Correct!Not quite. The answer is Small vessel engaged in diving operations.
Too small to show all the lights and shapes of Rule 27(b): all-round red, white, red, and by day a rigid replica of the code flag A, at least 1 m high. At night she looks like any vessel restricted in her ability to manoeuvre. You are on her port quarter. She is diving. Rule 27(e)
Question 8 of 10
By day: which picture shows a vessel not under command?
Correct!Not quite. The answer is Vessel not under command (making way).
Two all-round red lights in a vertical line. Sidelights and sternlight when making way. By day two balls. In the right picture you are on her starboard bow. Rule 27(a)
Question 9 of 10
At night you see these lights. Which way is she heading?
Correct!Not quite. The answer is Heading straight towards you.
You see both sidelights (and two masthead lights in line, if she has them): she is coming straight at you. She is a vessel being towed and you are right ahead of her.
Question 10 of 10
What is a "towing light"?
Correct!Not quite. The answer is A yellow light with the same characteristics as the sternlight (135°).
Rule 21(d): a towing light is a yellow light having the same characteristics as the sternlight. (Rule 21(d))
You have right out of answered.Ten of ten? The app draws every question new: other angles, other light, other wrong answers.
80+ questions like these in Lanterna
This page shows ten. The app has 80+ in this category, every picture drawn from the rules in changing light and angles, with the rule behind every answer, and mistakes that come back until you know them. Works offline.
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