Originally Posted by GordMay
See "Lightning & Sailboats" by Ewen M. Thompson.
Sea Grant Project #R/MI-10
Lots of other good web sources are searchable.
Bottom line: BOND EVERYTHING.
The link to the Florida University & the lightning research that was created still exists and is really, really helpful to read. (its brief & non technical).
I also just completed a US Power Squadron course on marine electronics which had one brief, but informative, chapter on lightning PROTECTION SYSTEMS. You can't stop a lightning strike but you CAN install a 'system' that provides 99% protection under a "cone." Its a three part system.... all really simple to understand... that works in conjunction with a fourth part called grounding which runs horizontal bow to stern.
The "strikeshield lightning protection system" is a commercial retail after market product that is attached to one's sailboat. I was doing some reading on it. The problem is: it seems to contradict the information from the US Power Squadron text. That is, the conductor running down the mast isn't supposed to jut sideways out over the deck. Lightning wants to do directly downward to ground and if you don't provide a low resistance path, it simply archs or jumps off the path to the path it wants to follow. Right angle turns of the after market system don't seem to be as safe as they imply.
Anyone know of any lightning strikes upon boats using that after market system? I'd bet its better than nothing, but I'm not yet convinced.