Davie
Your feedback provides the sort of information that landlubber modellers would otherwise have no access to. It is invaluable. Many thanks.
As far as models are concerned, the guys that build and sail them want to see lights working, and scaling the light output from model fittings necessarily reduces the impact that the lights make?
My feeling is that all but the scale purists will want to see navigation lights that are somewhat brighter than would otherwise be the case? (visions of old farts staggering around in the dark and falling into ponds everywhere)?
Personally, I've always been reluctant to use grain of wheat and grain of rice bulbs even at reduced voltages because they are filament lamps and often fail unexpectedly. The wiring 'tails' on these lamps do not aid easy replacement when routed down the inside of a mast, or through superstructure either. My own choice is for LED's, selected to have the widest viewing angle possible and with a larger value resistor than specified fitted to dim them acceptably. The benefit is that with a minimum 100K hour working life, they're going to outshine most modellers!