I bought a set of lights for my Mariner 19 and have been thinking about how and where to mount them such that they remain visible while heeling and the jib set. Either the top of the mast or the bow. Our schooner had the lights mounted on the cabin trunk. That meant they weren't visible when heeled more than about 8 degrees anyhow. Placement is terribly important, but I hadn't thought to check the limitations of the light itself.
Has anybody found a written regulation from the USCG about this?
Judy B.
From JD's posted PDF: "Annex I (COLREGs section 10 and Inland 33 C.F.R. part 84.16 “Vertical sectors”) prescribes the degrees and intensities that navigation lights must meet on the vertical plane."
I found it on page 122 of the USCG Navigation Rules and Regulation Handbook,
"10. Vertical sectors
(a)
The vertical sectors of electric lights as fitted, with the exception of lights
on sailing vessels underway, shall ensure that:
(i)
at least the required minimum intensity is maintained at all angles from
5° above to 5° below the horizontal;
(ii)
at least 60% of the required minimum intensity is maintained from 7.5°
above to 7.5° below the horizontal.
(b)
In the case of sailing vessels underway the vertical sectors of electric lights
as fitted shall ensure that:
(i)
at least the required minimum intensity is maintained at all angles from
5° above to 5° below the horizontal;
(ii)
at least 50% of the required minimum intensity is maintained from 25°
above to 25° below the horizontal.
(c)
In the case of lights other than electric these specifications shall be met as
closely as possible."
-Will (Dragonfly)