Red Lights at night
I remember the first time I learned about the “red lights” in the wheelhouse. I thought it was some kind of bad sailor joke having to do with ladies of the night, but after some personal experimenting, with the lights, not the ladies, I discovered that yes, I could read a chart with a red light and then look out into the dark and still see that other boat on the horizon. Mind blown!
Cruising at night has lots of challenges, and the one that matters more than the rest is your ability to spot danger in the dark. Keeping a good lookout includes actually being able to see. Night vision is your friend, but you have to guard it from the dangers of cabin lights and spotlights and alien transport beams!
The red light and night vision relationship has to do with rods and cones. I am not an eyeball expert, but there’s something about red lights and how far along the wavelength/spectrum/whatever that means they don’t bother the rods in your eyes, only the cones. I’m gonna link to a friend and better researched article here:
Sometimes I fantasize about putting red lights in my bathroom at home; I could stumble in there at night and then make my way back to bed without tripping over a slightly moved chair or barrel of rum that I forgot I commandeered.
Cheers and smooth sailing!