BOTH INTERNATIONAL & INLAND A 45-meter vessel is pulling a 210-meter tow. Which lights is she required to exhibit? A) two masthead lights forward and no after masthead light B) a masthead light forward, and two masthead lights in a vertical line aft C) three masthead lights aft and none forward D…

I’ll stick my head above the parapet. C) – because, so far as I can understand it, it says so in the rules: [Screenshot from 2026-06-03 14-49-37]

The USCG exam question pool (or the question in the pool circal 2010) agrees the answer is D.

Interesting. Can someone help me understand why? Does the question not exactly match the page I clipped from the rules, did I miss something? And if it does match, what in the rules page requires an aft masthead light?

C. Says three mast lights aft and therefore would be incorrect. Your observation on the aft mast light is correct and that is the source of all the confusion. The USCG has D. as the correct answer. All of the answers seem wrong to me and that is why I asked for help in the community.

The aft mast head light is optional and not “required” on a vessel of 45 meters. Many of my students are having trouble with this question and I believe it should be edited or removed from the pool. I believe all of the answers are incorrect.

Are they confusing the aft masthead light with that of a ship? I see the confusion when one could presume that a mast light is not the same as a stern light. i.e. the answer does not specify the aft light as being on a mast as are the three forward facing lights

Ah, well true, I didn’t consider that, but this raises another question for me. Where there aren’t “forward and aft” lights (i.e. if we don’t have the optional masthead light on a vessel under 50 metres), where is there a distinction specified between forward and aft masthead lights? What’s it forw…

See rule 23 - on a vessel 50 meters or more, the distinction between the fore and aft masthead lights are height, distance between must be at least half the length of the vessel, the aft light being higher. When I got my license the height difference was specified as 15 feet or more for a ship.

What's the answer and why? - Masthead Lights - #17 by Kennebec_Captain - Professional Mariner Forum

Topic		Replies	Views	Activity
Rules Question Worded Correctly Professional Mariner Forum	5	262	March 4, 2025
Rules Question… 500 Ton Master Upgrade	2	218	March 13, 2025
Barge lighting Tugs & Towing	2	1899	September 10, 2017
Huge Ship Light Professional Mariner Forum	5	14723	February 14, 2010
RAM Towing lights Question Professional Mariner Forum	3	813	February 9, 2024