I have a novel idea. There are NINE marks around the Witches. I suggest removing Seven of them altogether....keeping One Lighted mark at each end with a RED Slow Flashing light on top. (Not a Strobe).
Keeping things SIMPLE always seems to me to make more sense than making things complicated. Anything complicated usually results in unecessary confusion..especially when out there on the water trying to figure out WHICH of the current NINE marks you are closest to, and what to do about it..
Just a thought. NB