Marginally on topic
So, I finally installed my golden-plated swan neck fitting (to lead wires from mast inside) - well, based on price anyway.
Now, there were a few reasons to do so - the old fitting doubled up the wire which probably was not good for its integrity, plus it was small and I couldn't add anything else. But also - there was a persistent and significant water leak - which I attributed to the fitting.
Well, today, as I took it apart it became obvious that fitting was absolutely dry. Water actually leaked in inside the wire. Yep, thats it - the triple wire for the combined masthead/deck light conducted water between its outer jacket and the inside wires all the way inside the boat. I guess I have another thing to thank Ches. rigging for (it would be nice to create an uspide down loop in the wire before leading it down to prevent this sort of thing). Anyway, this just goes to show that water can and does travel inside wiring - long distance and in large amounts.
(Incidentally, my fix for this was to strip outer jacket from the wire as it exits the mast, so water now should drain on deck - we'll see how well it works)