My boat was struck a few years ago -- no damage to the CF mast, but it is bonded to a Dynaplate below with #4AWG wire (done at the factory at request of the first owner). I know the lightning came down the mast because there is what looks like a weld mark on the stainless deck-step plate, and I think it also came down the stainless shrouds. As you can see, it melted the stainless whip at the masthead (vaporized may be more accurate, as most of it is missing). The melting point of stainless is about 4,000 degrees f. It also literally blew the PL-259 connector off the coax and the screw-on connector ferrule went missing (how it unscrewed is beyond me -- it was also taped-over for water-resistance).

An interesting data point to consider is the shrouds and forestay don't go all the way to the top of the C-F mast. All parts of the rig were carefully inspected by a well-known local rigger after the strike (and the boat was hauled for careful hull survey) and all came up clean. The only damage was to electronics, and that damage was fairly extensive although not total. The boat has been used for another 3 years since that incident and I believe any undiscovered damage would have surfaced by now, if it existed.

I think this incident also debunked a few "urban legends": 1) the C-F mast didn't blow up from the lightning. 2) the Dynaplate didn't blow up from the lightning.