Just wanted to pass along an observation. I was sailing on a friend's P42 recently when we got to discussing the pitting which was appearing on his relatively new toerails. It reminded me of the kind of pitting that would be caused by an electric current, but how would electricity get to the toe rails ? Because there wasn't much else to do on a Caribbean afternoon (or because we're diehard techies), we connected a voltmeter from the battery's ground to the toerail. Nothing. Then we tried turning on breakers, until we got to the running lights and Bingo, 2.5 volts appeared on the toerail at midship. The problem was traced back to the running lights on the bow pulpit. Because the boat had made many passages, and possibly enhanced by night passages with lights on, the bow lights had seen their share of salt water. The rivets that held the light bulb mount inside the fixture had developed a crust of corrosion. This crust made contact with the stainless backing plate to which the fixture was mounted, which in turn is welded to the pulpit, which is bolted to the toerail. So on a night passage in even slightly rough seas, the deck would come alive with DC voltage. My 1991 P42 has a different style of light fixture which is much more effective in preventing this problem. The bulb, socket and wires are isolated to a single plastic mount. This plastic mount then screws into the plastic bottom of the fixture. I don't know the manufacturer's names, but perhaps someone can offer them if there is any discussion on this topic.