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In his book Sailboat Electrics Simplified, Don Casey has a succinct write up about boats and lightning. Included is a good discussion on proper bonding techniques (separate the lightning and electrical system grounds, easier said than done). Stray currents damage electronics if the grounds are tied together. It’s like arc, MIG, or TIG welding on a steel hulled vessel without disconnecting the electronics.
I’ve worked on a few antenna installations on buildings with coax isolators installed. One installation worked great, a crispy black antenna with no other damage. The other installation wasn’t so lucky, blown out TV, computer, etc. A lot of the randomness is likely due to directness of path, quality of connections, corrosion at terminals, size of conductors, etc.
Even if a boat is grounded properly, I think it would be more at danger on dry land. I’ve seen photos of boats in boatyards that had holes blown in the bottom of the hull because the lightning was desperately trying to get to ground. In the same vein as dragging a chain through lakes, if the boat will be stored on the hard it’d make sense to ensure a direct path to ground with a chain, cable, or wire.