A great project for those with failing eyesight, an interest in energy efficiency and a limited budget.
John Langford, Sabbatical2 - #172
I am halfway through replacing all the in the liner" interior lights with little puck shaped halogen units which throw off incredible light by contrast with the original incandescent units. I first looked through the marine catalogues and was stunned by the price of the Cantalupi and other marine brands. Cantalupi units that worked were priced at around $50 US apiece (West Marine). I found a kit of three small halogen units 2 1/4" in diameter for about $35 US per kit at my local lighting store. They were designed for valence lighting under kitchen cabinets. Halogens are 12v, so I discarded the step down transformer before installation. The units can be screwed into the liner just covering the original two-inch diameter hole. Each unit takes about 15 minutes to install including removing the original lights, rewiring, and drilling two holes. The results are outstanding! With a 10w bulb there is no problem with overheating. I think they could also be installed by widening the two-inch diameter holes in the liner and insetting the units because the units are less than 1" deep. I used the supplied wood screws, but I don't think that there is anything about these units that would make them particularly vulnerable to the marine environment.
As a side note, if the light over the dry storage area of the galley is replaced with a new "puck style" light it will have to be inserted into the existing space between the liner and the deck. If you attach it to the outside of the liner as I have done in all other cases, it blocks one of the cupboard doors from opening. Second, you might consider leaving a 20w bulb in the light over the icebox as you need all the light you can get to see into the bottom of the icebox at night. Finally, I haven't pulled off the lights in the forepeak to see if they are candidates for "puck" replacement, but if the hole through the liner for the wiring is less than 2 1/4" they should be.
The particular brand I found was called Gallery Halogen 20w 3-Puck Light System made in China and distributed by Liteline Corp., Concord Ontario. Again, the dimensions are 2-1/4 diameter and 5/8" deep. They come with white or black trim so be careful that you do not end up with a black set.