USCGQ
Log in Start free
USCGQ
Toggle sidebar
Home
Deck
Rules of the Road
#1575
Random Next

Deck: Rules of the Road

Question 1,575 of 1,025

BOTH INTERNATIONAL & INLAND You are heading due east (090°) and observe a vessel's red sidelight on your port beam. Which direction may the vessel be heading?

0 ✓ | 0 ✕ 10 free left today

Tip: press A-D to answer

More Rules of the Road questions

Mariner discussion

Comments from mariners who studied this question.

nc ncalcamu · Jan 4, 2016
no comments
gi gibbo8489 · Mar 26, 2019
This is terrible. Why is it not NW?
Pa Patrickg · Apr 2, 2019
It should be northwest. If it was southwest you would observe both sidelights.
Ra Rad1687 · Apr 23, 2019
So which is the correct answer? NW or SW?
Je JeffR · Jun 23, 2019
SW (225 deg) is the correct answer. I draw pictures on a maneuvering board to help. But you can think of it this way: If you are meeting another vessel in a red to red, or port to port meeting situation, the other vessel is going in an almost opposite direction. In this case the other vessel would be travelling on a course as close to 270 deg as the answer allows. If the other vessel was travelling NW you would not see red light, only a stern light. Draw it out and remember your Arc of Visibilities. I hope this helps.
Ri RickC137 · Jun 12, 2020
The reciprocal of your course is 270. If the other vessel is on your beam on course 315, that is a 45 degree difference. The sideight would only show 22.5 aft of the beam. Anything more than 22.5 degree difference and your looking at a stern light. Only way to see both sidelights would be if the orher vessel was on course 180.