Great response and information. Just a comment and an anecdote. I’m a sailor and have owned several brands, all equipped with similar “aluminum lightning rods” parading as masts. Interestingly there are two different thoughts on lightning safety on sailboats. Beneteau believes that the aluminum mast on a FG boat should be grounded to the lead/iron keel to provide a low resistance path to ionized water and so connects them with a heavy cable. Catalina on the other hand does not connect the mast to keel as they believe that a.) it is less likely to attract lightning if it is not grounded and b.) that grounded masts like on a Beneteau often become poorly grounded over time from corrosion at connections which then become giant hot spots and melt holes in the boat. There have also been reports of lightning strikes going right through FG to get to a big hunk of grounded metal inside the boat. But Catalina does suggest that if you don’t agree with their approach, that in a storm you attach some jumper cables to the stainless rigging and dangle them over the side of the boat. So obviously there is no perfect solution or conclusion is available from the boating industry.
Finally, in support of the 17 meter rule, I remember camping in the Sierras with my parents in an aluminum trailer parked near some tall redwood trees. During a thunderstorm a lightning bolt totally ignored both the redwoods, and thankfully our trailer, and totally smoked a little 3-4 foot tall tree out in the middle of a clearing which I’m guessing was at least 17 m from us and anything else. That sure got my attention! Safe camping, everyone!
Bruce & Joanne