(Larry W4CSC) wrote in message ...
Even if you have a wooden mast, it will have antennas, stay metal
cables, electrical lighting wires and other things up the mast that
attract Mother Nature's St Elmo's Fire.

If you take a lightning hit, lightning WILL go right through your
hull, no matter what it's made of, to get to the ocean ground. The
only way to keep it from blasting a hole in the hull is a proper
grounding system on all conductive standing rigging with proper
grounding straps and underwater grounding blocks to bypass you and
your boat. If you have a lead keel, there's the best underwater
grounding block you'll get. If not, buy those metal grounding blocks
and bolt them through the wooden hull as the instructions show. The
bigger the ground straps, the better. Make all turns in the straps
SMOOTH NOT NEAT! Lightning doesn't turn corners well. Those
super-neat folds and sharp corners render any grounding for the huge
EMP pulses nearly worthless. It'll jump right out into the boat where
the 90 degree corner is placed, tearing it all to hell. The longer
the curve to turn the strap, the better.



On 11 Mar 2004 01:09:00 -0800, (gaffcat) wrote:

I am building a wood 40' sailing catamaran. The mechanical propulsion
will be an outboard. I have read a lot about boat wiring and they all
talk about having a ground connection on the engine block thereby
making a connection to ground through the propeller shaft etc. With an
outboard I will not have a permanant connection to the water ground so
do I need a separate ground connection to somekind of conductive
wetted surface? I have been designing the boat to not have any
underwater metal pieces, do I need one? ABYC and USCG regs talk about
ungrounded systems but not the pros and cons or implications.

fritz


Larry W4CSC
POWER is our friend!

Recently I read a good article on how (not) to prevent lightning. You
can find it he http://www.panbo.com/yae/archives/000344.html

A quote from the article:
"You may, at this point, be interested in a Lightning Protection
System (LPS). But it's a misnomer, as there is no proven way to
actually protect a boat from lightning, only a technique for limiting
damage when it strikes. Actually, there is a widely held myth,
particularly among sailors, that an LPS—which is primarily a straight,
highly conductive path from mast to water—causes more harm by
attracting lightning than it does good."

Yme
http://www.panbo.com/