I had some great success with this so I thought I'd share! My goal was to create bright, efficient, and more importantly, inexpensive lighting for my sailing dinghy without dropping in a 12V lead acid battery for incandescent bulbs.
Here's what I used (besides tools):
Attwood 3121 navigation...
I'm looking all over the web and in stores for the perfect LED lantern to hang from the middle of my boom to light my cockpit while at anchor, on a dock, or motoring.
- 12v; car-lighter type plug (no batteries, solar, chargeables, etc)
- LED (warm white color, not cool )