Originally Posted by MarkSF
"via switch (perhaps nav lights; you have these for night sailing when you need a compass
light, correct?) and fuse or breaker from the house bank."
I think I would like to have separate breakers / switches for nav lights and instrument lights, for the simple reason that I don't want a fault in my instrument lights preventing use of the nav lights.
Most modern instruments have LED backlighting, powered and switched, by the instrument itself.
Wired properly, there should not be an electrical
circuit failure for the life of the vessel. In the event of a fault, proper current
limiting would open the compass
circuit, should a short circuit occur which could otherwise affect the running light circuit.
I connect compass lights to nav running lights all the time.
If one wishes them separate (e.g. to reduce vessel visibility nightsailing in pirate waters), it could certainly be on a different switch, but this is not usually a consideration. Normally, if one needs the running lights on, the compass light should be on, and if one doesn't need a compass light, they don't need running lights.