Originally Posted by noelex77
...My LED Owl is much brighter than the masthead anchor light fitted to most boats (and I have 2) It will even illuminate boats anchored close to me.
This got me curious. My Missouri handbook says : "a white light visible from" blahblah...
You're using two. If I could use two I wouldn't have to worry about anything on the masthead where I am. So I dug out the final authority, the ColRegs. Colregs says (fresh water)
(a) a vessel at anchor shall exhibit where it can best be seen
(i) in the fore part, an all-round white light or one ball(b) a vessel of less than 50 meters in length may exhibit an all-round white light where it can best be seen instead of the lights prescribed in paragraph (a) of this rule
(ii) at or near the stern and at a lower level than the light prescribed in subparagrah (i) (emphasis added), an all-round white light
(c) A vessel at anchor may, and a vessel of 100 meters or more in length shall, also use the available working or equivalent lights to illuminate her decks.
The illustration attached shows the aft "all-round" light clearly mounted behind, and partly obscured by, the bridge.
So my original post was based on an error; I thought that I could only have one anchor light (from my Missouri book) and knew that it could not be seen over 360* due to obstruction from my fat mast.
All very interesting.