It is my very firm belief that you should NOT fit navigation lights to your hull, as they would give you a false sense of security, being so close to the water level. In all but flat calm seas, these will be invisible to other vessels. I believe that flying a white 360 degree light from the masthead offers a perfectly legal, and practical solution. This light is the same that a vessel at anchor would show, and compared to other vessels moving at speed, that is not a bad thing to be mistaken for.
As regards fitting such a light, I bought an inexpensive LED white light, which is powered by 3 D size batteries. I then added a white PVC plumbing connector piece, which nicely fitted over the masthead (warning, this method is incompatible with the Hobie spinnaker kit, and I have not yet devised a suitable solution) I then added a small block, with its mate attached to the furling drum at the bottom of the mast. I cut two "keyhole" slots in the mounting tube of the light, and added matching knots in the halyard running between the tweo little blocks. Once the knots are inserted into the keyhole slots, I can then turn on the light, and hoist it until it is at the masthead. A surprise bonus was that the light also illuminates my msthead wind indicator, which makes night sailing lots easier!
