today i was catch on the sea from an heavy rain...
what's happens if a lighting hit the mast of my hobie during a sail ?
Follow this link for more electrifying information 
http://www.catsailor.com/forums/sho...
Jeff
More shocking news.
This was the link I meant to put in.
http://www.catsailor.com/forums/sho...
Jeff
You can do away with navigation lights at night for two reasons 1. You will probably "glow in the dark" and 2. You may not be around to worry about it.
On a more serious note, lighting strikes on cats are not a common occurrence (although it does happen) and of the two times over 45 years of continuous sailing that I have been witness to such an event, both sailors came away "shaken" but relatively unharmed otherwise. Their masts on the other hand were "history".
The mast to the water "seems" to create a good "conduit" for the lightening to travel without causing an enormous amount of peripheral damage.
The two times that I witnessed actual strikes on cats, at both times the skippers had their aluminium tiller extensions trailing in the water which could have created an “earth” for the lightning. There is a lot of conjecture that when a cat is NOT “grounded” the mast acts as a repellent to any strike as the charge emanating from the top of the mast is the same as that of the lightning and repels it (or visa versa). I tend to agree with the hypothesis, as I have witnessed many, many, times cats sailing when there have been many strikes on the water around them but with no direct “hits” to the cats.
Carbon fibre boats and mast are a little disconcerting to me now though as carbon is such a very, very, good conductor of electricity.
When I bought my H-16 in 1985, I received a letter from Hobie offering to retrofit my mast with the Comptip mast. One thing that was said in the letter was that it would reduce the cone of protection from lightning by shortening the aluminum portion of the mast. I found information on a web site about sailboats and lightning where the author said the only thing more dangerous than being out on the water with a boat with a mast was to be on one without a mast. From all this I take it there is some protection from the mast but it is better not to be out there.
Howard
Why is there no real science to this? Common knowledge seems to have some real foundation in history ... yet there is no accepted scientific direction with regard to sailing in lightning.
Can you imagine the "paper" on the subject?
"Do yacht masts, attract lightning, repel lightning, or are ambivalent to lightning), (should all sailors do away with "masts" and just use sails alone??)
Besides, no "drug company" could see any profit in funding any such scientific study, and with out funding, no study! And governments seem more interested in funding studies on things like “how many times a minute does a fly in season beat its wings, and the overall effect that any variation has on the Ice flows in Antarctica”.
(I’m not REALLY cynical, am I ????)
Does that study involve just Australian flies? Sounds plausible to me. 
And if your flies can help melt the Antarctic ice, maybe Rick and I would end up having waterfront property again in Key Largo. 
Please don't kill flies.
(I'm not REALLY cynical, either; am I?)
As far as lightning, I think you are safer on a sailboat than on a powerboat, and you are safer ON a sailboat on the water than anywhere NEAR a sailboat on land. Despite all the threads on this forum about lightning, and all the links to research, nothing is really definitive on this subject.
If they could harnessed the “energy” from just the flies around the backside of one cow in Western Australia it could solve the whole worlds “energy” problems for the next 100 years (and that’s without any “funded “ study)
Now the problem is how to get a harness on a fly.
Not that I believe this will further your discussion, but superglue is the standard way to harness a fly.
"Do yacht masts, attract lightning, repel lightning, or are ambivalent to lightning), (should all sailors do away with "masts" and just use sails alone??)
In my experience, there does not seem to be an inherent attraction between lightening and 'tall' objects, even tall metal objects. I live in central Florida, one of the lightning capitals of the world, on 32 acres with forest, cleared land and lake. My property is frequently struck, almost daily during summer. Yet it strikes the flat ground as often as anything else. In fact, there is a sort of 'hot spot' about 100' X 100' between the house and barn that has been struck no less than 5 times this year! I've got eyewitnesses and the burned grass to prove it!(it burns the grass in the most peculiar way!)The ground in this spot is flat and grass covered. Why strike there and not the grounded 40' power pole a couple of hundered feet away, which has not been struck once this year?! Maybe an object has to be REALLY tall, like a few hundred feet or more, before it makes any real difference. This probably jibes better with the physics, anyway. I mean, if the charge has just traveled through several thousand feet of air, of what real importance is another 30 feet one way or the other?
Jimbo
Also, on all of the beach cats I have seen unless the dolphin striker is in the water there is no direct connection from the mast to the water, even with an aluminum hiking stick.
Lightning is a funny thing and we (people) don't know much about how it behaves. Anything that can penetrate a few hundred or few thousand feet of insulating material (air) can do whatever it wants to do.
I'm not even so sure grounding in the normal sense makes any difference. Now of course the charge is seeking ground, but when you are dealing with an electrical pressure of 10^7 volts, what constitutes 'insulated' and 'grounded' is certainly very different than it is for the voltages with which we are familiar. You would have to check resistances in the 10's of megohms to see what constitues a conductor or insulator. Even then most materials undergo some sort of breakdown (ionization, carbonization) at those pressures so the resistance would change if actually struck by lightning.
I just stay indoors or sit in my faraday cage 
Jimbo
No worries Mary, they are really BIG FLIES!! When they combine into "packs" they have been know to carry the cows away!!!
(A bit like in Texaz - where everything is BIG)