Copy Write 3/3/2002 © Updated 2/13/2006
The longer I sail the more I become concerned about lightning.
The more I learn of lighting management the more confusing everything gets.
There doesn't seem to be a clear advantage one way or the other grounded or ungrounded.
One thing I have learned even grounded, damage probably will occur. It seems giving lighting a place to go is preferable to allowing it to find it's own path.
Keelboats have it easy; swing keelers things are more complicated.
Smaller boats things get even more difficult.
The old standby of attaching a set of jumper cables to the mast or rigging starts falling apart upon close inspection of how lighting may jump around the mast and standing rigging. On a previous boat for a while I did carry the cables, soon discovered how quickly the salt environment compromises them.
There seems to be several aspects of lightning management
Grounding the boat to give as direct and easy path as possible for a hit
Bonding the other metal areas of a boat to allow them to dissipate a charge.
Notes General ramblings before I start actually doing anything
Grounding wire according to my information needs to be as straight as possible and no sharp turns or bends also a short run to the grounding plate; 4-gauge stranded marine wire seems acceptable.
Also according to an article I read recently, if possible the grounding wires should be inside some non-conducting tubing. Non-conductive tubing sounds a lot like PVC. The theory was a secondary line of insulation in case the lighting fried the insulation on the wire. Sounds reasonable to me, except PVC burns, should the lightning ignite the PVC potential problems. Of course I have a fiberglass boat and the same thing could happen to any nearby fiberglass. I will check around some more about this.
The real concern is how to connect the boat to the seawater.
At this time I do not have "THE ANSWER" only several ideas.
Bonding is different but related to grounding, until recently I failed to understand the difference.
According to my understanding bonding connects all the possible electrical conductors together and channels that to the ground.
Should a charge build up the bonding will dissipate the charge.
Side stays are bonded together along with other areas of concern.
According to my information 8-gauge wire is acceptable for grounding, no sharp bends or kinks.
If you have some ideas for grounding or bonding I would be most interested in hearing them.
Before you can understand why some of this needs to be done a better understanding of how lightning works is important.
I don't intend to re-create the wheel, check out some of the Lightning Links below or do your own web search.
Some Lightning links I found helpful
Lightening & Boats
Lightening & Sailboats