Any time you wire a mast ALWAYS put a drip loop in the wires. If it's at the top of the mast simply run the wire bellow the actual hole and then back up to it. If it's deck stepped you can also do an additional internal drip loop at the mast base with the entire bundle of wires. I usually just nick (as in very small nick) the jacket at the bottom of the drip loop so any water in there can weep out..
Well, when my mast comes down next time (may be August, I need to fix the halyard) I'll make sure this wire gets re-wired properly. As it stands, this was a "professional" job by Chesapeake rigging. I am sure there is more crap like that they did, I am just finding out.