strike is more complex than you might think. It involves power gathering in a large area (both in the clouds and in the gorund) and then charges flowing both ways. When a charge builds up in the ground, it builds up in a large area--like a "pond" of ions in the ground. Similarly when it lands, it discharges "out" not just "down", spreading through an area.
And that's just the electrical
half. Whenever you get large amounts of electricity flowing (I round it off to a kajillion volts or so) the moving electricity creates magnetic fields in any nearby metal object--and when those collapse, they create new electrical surges called "inductive surges".
So, bottom line, is that anything near a powerful strike can suffer damage from inductive surges even if the lightning
doesn't hit it directly. While this is not "common"...neither is lightning zapping you at all.<G> I don't say it did happen to your boat--only that a strike within 100 yards *might* create that kind of damage. Either indirectly, or from a surge in a power cord that might have been plugged into the boat's systems, etc.
Lightning is funny
stuff--no pun intended.
WRT protecting metals? Simplest way is a little grease. Best grease for this purpose is silicon grease, aka "silicon dieletric grease" (meaning, it doesn't conduct at all, unlike Vaseline which conducts a little) aka "silicon brake grease" (essentially the same thing, sold for use in auto brake parts
because it is stable at high temperatures) and even called "light bulb grease" because you can grease light bulb sockets so they won't gall and stick.
Cheapest source is the auto parts
store, about $5 for the BIG 4-8oz.tube, instead of $3 for the 1-oz. tube in the marine
store.<G> Big advantages over other products?
Inexpensive. Easy to clean up or wipe off. Non-migrating, non-staining, very stable. And if you need to get down to the bare metal or open up a connection--just wipe it off, no scraping needed.
Great stuff, don't tell anyone.<G>