Most folks "see" lightning as a flash or bolt, but that's just the breakdown of the ionized column, after the damage is done. Usually the current is going up from the object, following the column. It's not like getting hit with a bat but more like getting ran over by a truck from behind while walking down the road. If you could lay down on the pavement the truck could go all around (over) you and not hurt you, but if an arm is sticking out, ouch ! Lightning doesn't jump to an object, it uses the item as an easier path, and the spark you see is when that path is disrupting. Imagine being in a conductive atmoshere where some things are more conductive than others. The current can travel through the ionized air, but a radio is more conductive so it gets used as an easier path, even if it's not connected to anything. People are not very good paths luckily and usually just get the "fuzzy" feel. My personal experiences with lightning are many and firsthand, and linemen have to sit through countless hours of lectures by THE most knowledgeable people in the electric utility industry, neat stuff.> From: swansong@gmn-usa.com> To: passagemaking-under-power@lists.samurai.com> Date: Fri, 23 Mar 2007 13:05:06 -0400> Subject: Re: [PUP] Lightning preparedness> > Scott has many good points that might help prevent or mitigate the damage of> lightening.> > However, in many miles of deliveries up/down the East Coast, Gulf, Atlantic> and Caribbean most of these points would either keep you blind or have the> boat less serviceable that you may wish for the delivery. Radio antennas> need to be up and most of the nav gear is on.> > It is not unlikely that one can be passing thru an area that has many> thunderstorms one day after the next.> > We, Swan Song, have a spare VHF unconnected to anything which could be> installed if we lost the online units. 2 spare GPS units and a sextant.> > What would worry me the most is the lost of the microwave, dishwasher and> trash masher. Then the water maker so we'd be stuck with only 300 odd> gallons of water. Of course the Air conditioning unit are fried as are all> the on line bilge pumps....good thing we have a few spare one in boxes.> > So we are stuck hand steering with a running ancient smoking oil spewing> Detroit Diesel eating the fish we catch on the way. We are working on the> hand steering by fashioning a "tiller pilot" style of auto pilot that would> connect to the emergency tiller. It would give us about 10 degrees +/- of> helm control.> > The area we are sadly lacking is in collision repair. We have no mats, no> air bags and just a couple of gallons of underwater epoxy and a small supply> of adrenalin. We do have 2" plus of fiberglass below the water line and up> the bow about 3 ft. Then it tapers down to 1" at deck level and 1/2 at the> top of the gunnels. Tough stuff.> > We are looking at a direct drop into the sea cable from both sides of our> radar mast spreaders. Thoughts run from using 3/8 galvanized wire rope to> copper which corrodes badly from our experience. However we want it to be> outside the boat. Trying to direct a hit down thru the inside of the boat to> a plate on the hull is asking a bit much of the lightening, IMHO. It may not> oblige and side flash to everything on the way down. Then again it may do> this anyway.> > We are an unbonded boat including the engine, thruhulls, tanks, etc. So> there is no reason for lighting to want to pick something inside vs. outside> to flash to.> > We had several boats over the years which have been hit and the bonded boats> have always faired less well than the unbonded ones.> > As always YMMV as my experiences are .00000000000000001% of the overall> picture ;-)> > Cheers> Dave & Nancy> Swan Song> Roughwater 58> _______________________________________________> > Passagemaking Under Power and PUP are trademarks of Water World Productions, formerly known as Trawler World Productions.> > To be removed from the PUP list send an email with the> subject "unsubscribe" (no quotes) to the link below:> > mailto:passagemaking-under-power-request@lists.samurai.com> > Passagemaking-Under-Power Mailing List _________________________________________________________________ Your friends are close to you. Keep them that way. http://spaces.live.com/signup.aspx