Rules of the Road: BOTH INTERNATIONAL & INLAND Which light(s) are required to be exhibited by a 20-...

this is stupid because two of these are optional and the question says required....

The question clearly states a "20 METER SAILING VESSEL" BUT Rule 25 is for less than (20 Meters) The stern light is required underway, the green over red on the mast is "optional"

Rule 25 says ‘ a sailing vessel underway shall exhibit sidelights and a stern light. That means any sail boat. It goes on to state in (b) less than 20 meters can combine the lights Orin addition carry more. But that doesn’t mean above 20 meters doesn’t need the side lights. Anything below 20m has options but over 20 M they’re carri g side and stern lights. Makes no sense otherwise. You could then have a massive 200 foot sailboat with only a stern light on and a much smaller boat better lit. In my opinion they got this wrong.

This is the Coast Guard we are talking about guys lol. The question is not asking for all the lights required for that particular vessel. It is asking you to choose the required out of the ones listed options "A" and "C" is an either or situation but "B" is a mandatory. At least that's the way I understand it.

25(c) - "A sailing vessel underway MAY, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit at or near the top of the mast, where they can best be seen, two all-round lights in a vertical line, the upper being red and the lower green, but these lights shall not be exhibited in conjunction with the combined lantern permitted by paragraph (b) of this rule."

25(a) "A sailing vessel underway SHALL exhibit:
(i) sidelights;
(ii) a sternlight."

LESS than 20 meters can combine sidelights and stern light in a tri-color masthead "combination lantern". This vessel IS 20m. Stern light and sidelights are required, R/G masthead optional. A combination lantern is not allowed.