I think what Zach is asking is not the range or the horizontal arc
but the vertical arc
. This would matter if the vertical arc of the nav light is less than the boats angle of inclination when heeling.
Zach, that is something you would have to check with the manufacturer or check it out for yourself. I believe the International Maritime Organizations (IMO) specs for navigation
lights put into their specs a pretty broad range of vertical arc to cover vessels that either heel or roll from side to side in severe weather
or while sailing, but I have no idea of the specifics. None the less, if you want the light to be legal
, it needs to comply with IMO standards. Ask the manufacturer if it complies with IMO standards for a combined port-starboard light for a vessel under 12 meters in length...if not, I would walk away from the product. There are other LED lights
out there that do meet IMO specifications.