For years I worried about lightning strikes on the boat, yet there weren't a lot of places where we experienced electrical storms, though when we did, they were terrible. *I've just found a report that is most interesting to me: NASA's plotting the areas of the globe with the highest lightning activity. *There are lots of sites on the Internet reproducing this information, one*HERE
Here's the information in one graphic: *
Florida is one of the most active parts of the U.S. for lightning - hmmph! *No wonder US boats seem to be so paranoid about lightning. *And as all the comments regarding NASA's data point out, it's on or near land that electrical storms happen, it's clear to me that this is one more reason to head offshore and enjoy the blue water passages. *And for Brenda, aka Redbopeep, you'll notice that in general, lightning is not a problem in high latitude sailing. *Go for it!
Here's another tidbit of information I recently learned about lightning and lightning rods: *pointy is not as good as blunt for ATTRACTING lightning. *So now I'm reconsidering the Forespar Lightning Master mentioned by Osirissailing. *Maybe that would work after all. *
Because the link won't work, I'm pasting the article here:
Article in New Scientist Magazine, 27 May, 2000, by Jeff Hecht
"KING George III was right and Benjamin Franklin was wrong, at least when it came to the tips of lightning rods. The American scientist and diplomat believed lightning rods, which he invented in 1749, should have pointed tips, and his design has been used for over two centuries. But tests on a New Mexico mountain top show that blunt lightning rods, which George III decreed be used on royal buildings, are actually more effective at attracting lightning.
Electric charge builds up during thunderstorms, and Franklin's original aim was to prevent lightning by dissipating this charge, says Charles Moore, a retired atmospheric physicist formerly at the New Mexico Institute of Mining and Technology in Socorro. Franklin knew from his indoor experiments that earthed, pointed rods could discharge a nearby charged object without a spark. But when he placed a rod outdoors, he found that instead of preventing lightning strikes, it attracted them. Undaunted, he realised that attaching a conductor to the rod could divert the strike harmlessly to earth. This remains the basis of lightning rods today, although a perfect design has never been agreed.
In the 1930s, researchers showed that when a sharply pointed conductor is in an electric field, it is "protected" by a surrounding cloud of ions that reduces the local field strength. Moore wondered if rounded tips would better attract lightning because they lack these ions.
"We ran a competition between sharp and blunt rods," with tips from 0.1 to 50 millimetres in diameter, he told New Scientist. During seven summer thunderstorm seasons, he found that the ones struck most frequently had tips around 19 millimetres in diameter. The rounded rods invariably attracted lightning away from the pointed rods, none of which were hit. Moore calculates that the electric field strength above a 19-millimetre blunt rod is higher than that over an otherwise similar sharper rod, making it better at attracting lightning.
George III had no great insight when he insisted on blunt rods, Moore notes. "He did it out of political pique," because he was angry at Franklin for his support of American independence. "Franklin was right in putting up a conductor," he adds. "We just fine-tuned him."
Source: Geophysical Research Letters (vol 27, p 1487)"