David Lynn (S/V
Nine of Cups, justalittlefurther.com) wrote a story for the most recent Good Old Boat magazine where he claims the proven best lightning prevention technique is standing on one foot, patting your head, and rubbing your belly (all at the same time). Using this method their boat has never been hit by a direct strike.
But seriously, it may be as clever as any other strategy. When you are dealing with several thousand amps and several
hundred million volts, anyone claiming to know what lightning will do or how to make it behave is lying thru their scorched teeth. And the competing camps will all insist they are right: You want a fat, straight, single path to the keel. No, you want multiple smaller paths to many grounding plates. No, you want to isolate the mast and rigging entirely from the grounding potential, so it is a resistor & lightning will ignore it.
Nothing new, BTW -- it is an argument dating back at least to the mid 18th century.
Toss in the various gaizmos sold to nervous sailors (dissipators, voltage clamps, etc. etc.) and consensus best practise wafts even further away.
First thing to consider is how many sailboats there are in the world, most with tall metal sticks on them, parked in moist flat areas, yet how few of them actually take a strike that causes structural damage or injury. Golf is more attractive to lightning than sailing.
Second thing to note is that some sailboats DO take direct strikes that result is structural damage. I know of at least two that had holes blown thru their hull
while parked on dry land with the mast down. Nearby boats, on land or water, with spars erect were untouched.
Third thing: Lightning will do whatever it pleases, and you cannot stop it. There are some ways to minimize your exposure to lightning, some ways to direct a small bolt with some degree of confidence, some ways to protect crew and individual components (spare GPS units, handheld VHF). But in the end I'd suggest you might take an actuarial view rather than a engineering view. Your odds of getting hit by lightning on a given sail, or in your sailing lifetime, are probably less than your odds of being killed by a falling tree. And there is precious little evidence anything you do to lightning-proof your boat will make a whit of difference should that one thunderbolt with "
Gancia Girl" written on it come knocking. Another round of gin and tonics may be the best approach. "Here -- these cocktails have proven lightning-deterrent effects. I've been drinking them for years. But you have to use
Gordon's gin, or all bets are off."
