"Richard Casady" wrote in message
...
On Tue, 19 Aug 2008 16:53:34 -0700 (PDT),
wrote:
Line Squalls are a different matter but I have always managed to avoid
being on the water when they were around.
It is not unheard of for an airplane to travel hundreds of extra miles
avoiding thunderstorms. They are also fast enough to, with the aid of
ground radar, as well as onboard, find a hole in the line. Or outrun
it and land and let it pass. Thunderstorms cause planes to crash. They
break the wings off. They can also turn a plane into a giant
hailstone. Rather be in a decent boat, one with a lightning rod.
Casady
I don't know if I would want a lightning rod. I know it's a subject of
debate, but I hear of too many stories of dedicated grounding plates on the
hull (to which the lightning rod is attached) being blown right out of the
hull due to a strike. Boat sinks. If not connected to a dedicated
grounding plate, and attached to the boat's regular bonding system, results
can still be the same, or, at a minimum, taking out all your electronics and
possibly starting a fire.
If I had a sailboat with a conductive mast, I think I'd install a large,
round metal ball on the top ... similiar to those used on flagpoles. The
round shape of the ball minimizes the static charge potential that leads to
a strike.
The new, old boat I recently bought has a "lightning diffuser" or some such
device installed on the tubular, aluminum radar arch structure. I pulled
out the manual on it, not completely sure I wanted it on the boat.
It is essentially a stainless brush, a rod with stainless steel bristles
coming out around the rod for it's full length.
The concept is that a static charge builds up on object about to be hit by
lightning. If the charge is concentrated on a sharp, conductive object, the
potential builds higher and the chances of a strike is increased. The
large number of stainless bristles on the device is supposed to diffuse the
charge, preventing a single point from getting too high in potential.
Makes sense to me and since it is a totally passive device (not powered ....
just grounded to the arch) I left it on.
Eisboch