Originally Posted by Maine Sail
The bare minimum size for the wire used under ABYC standards would be 16GA. This is as much about durability as voltage drop. With 16/4 you won't have any voltage drop issues with LED but if someone were to ever convert back to incandescent then it very likely would not meet the max 3% drop for nav lights. If these are LED USCG Cert fixtures then you won't be worried about anyone swapping bulbs.
I won't put 16GA in a spar for navigation lights. The weight of the wire is often loading the strands and mast wire can get beat up pretty well. I just spent a day a few weeks ago re-wiring a spar because small wire was used and the mast was incandescent. He had also lost the wind instrument and I found one of the small 18GA wires in the bundle had snapped where it was attached to the top of the spar.. I generally leave 16GA for non-critical stuff like stereo speaker wiring...
I would stick with your 14GA. If the wire is in a conduit, not swinging free, then 16GA could certainly work but I prefer 14 GA +.....
I get the large wire is less likely to break. so how are the ABYC saying to connect the small wire pig tales that come on most of the new LED light fixtures. what about the breaker size, if you use a 15 amp breaker like most panels come with the 14 ga is good but the small pig tale will become fused link at the fixture end and the smaller wire is still a place for breakage. the smaller wire is more likely to be the one that will chafe through where it passes through the aluminum mast. also not finding that any of the LED lighting fixtures are ABYC approved