One thing that I’d highly recommend for all cruising sailboats is upgrading to LED-based lights. This is for two reasons. The first is that upgrading to LED lights can reduce the electrical load on a cruising sailboat significantly. The second is that LED-based lights are lower maintenance and lower cost over the long run. You can now get LED replacement lights for both cabin and navigation lights.
However, there are some caveats to going with LED-based navigation lights. I would recommend only going with ones that have met USCG certification. The reason for this is simple—if you are involved in a collision, having lights that were not USCG-certified may open you up to additional liability.
On most boats, 25-65′ LOA, the least expensive way to get LED-based navigation lights is to purchase AquaSignal Series 25 or 40 navigation light fixtures and then replace the bulbs with the LED-replacement bulbs made by DR. LED. The DR. LED/AquaSignal fixture combinations have been USCG certified. I am using the Dr. LED replacement bulbs on the the deck level bicolor and stern light, since they are AquaSignal 25 fixtures. I am also going to replace the steaming light with one as well.
EDIT: I recently found out that the only USCG-certified Dr. LED fixture/replacement bulb combination is their Polarstar 40 with the AquaSignal Series 40 anchor light. The rest are not USCG certified. In their place, I’d recommend using the AquaSignal Series 32 LED fixtures, which are certified. Be aware that many other LED fixtures, including some of the other AquaSignal model lines, are not USCG-certified.
You can also go with the purpose built fixtures, by Orca Green Marine, Lopo Lights, or several other manufacturers, but I’ve found that these are generally far more expensive than going with the AquaSignal/DR. LED combination. I have the Orca Green Marine Tri-Anchor/Strobe masthead light fixture on my boat, shown below—
but the DR. LED/AquaSignal combination wasn’t available when I was fitting her out.
Of the replacement bulbs for cabin lights, the best are probably the SensiBulb brand LED-replacement bulbs. They can be retrofitted to many different light fixtures, including those that use halogen MR-10 or dual contact bayonet bulbs. While the SensiBulb brand are slightly more expensive than some of the other brands, the quality and color of the light they provide is well worth it in my opinion.
Why Use LED-based Lights
The fact that LED-based lights can use up to 80% less power than their incandescent counterparts means that you can often go longer without re-charging the batteries. This can make a significant difference on a longer cruise. It means that you put less wear on the engine for battery charging. You can often get by with a smaller house bank.
Many boats can cruise and re-charge their batteries using purely passive means, either solar or wind, or a combination of the two, when equipped with LED-based lights. This conserves fuel and allows them to be more self-sufficient, which means lower costs cruising in the long run.
The lower maintenance aspect of LED-based lights is something worth noting as well. It means that you’re less likely to need to go up the mast to replace a blown light bulb. It means you can get away with carrying fewer spares.