Does your boat have lightning protection?

[mike]

Just curious as to what everyone else does regarding lightning...

[mgg4]

Out here in California, we don't get that many thunderstorms. Lightning is not as frequent as it is in the midwest.

I normally choose not to go out when there are storms in the forecast. If I were cruising, there is no way I would have a boat that didn't have some sort of lightning protection. My boat is a fair-weather boat (at least the way I use it), and so I don't think grounding the mast is worth the hassle. At least for me, anyway.

--
Mark Galbraith
Mac26X "Offline" (2002)
Oakley, CA

[mike]

Down here in Louisiana, the forecast gets stuck on "highs in the upper 90's, 20 - 30% chance for scattered showers and thunderstorms" pretty much all summer!

--Mike

[Gary]

I am planning on using an arrestor that I read about on the net. It is basically welding cable looped around the base of the mast and dangling in the water on both sides. It does not ground the mast but gives the current an easier path to ground in case of a strike on the mast. The article didn't specify what size of cable but I imagine it would be the biggest you could coil and store. Probably be a mass of goo if it did divert the current but should be better than having it try to go through the boat. The web page if your interested is:
www.stewartfam.net/arlyn/lightning2.html

[Jack O'Brien]

Florida has more lightning than any other USA state and the average bolt here is 50,000 volts versus 35,000 volts for other states. It can rain on one side of the street and not on the other. Thunderstorms are a daily occurance in summer and to not go out during summer here would be like not going out in winter up north.

If out for a week's cruise to the Keys or Bahamas, or wherever, the storms will find you. We had a dandy run over us at night anchored at the Dry Tortugas. You don't get up and run away from it at night in shallow waters. So you hunker down and stay away from metal.

I don't know which hypothesis is correct but, I have two sets of heavy jumper cables and a couple good-sized pieces of heavy-weight, expanded aluminum for ground plates. Have only used these at anchor - don't know how bad they would bang the hull when moving. My hope is this system would lead a strike outside the boat rather than down the mast compression pole and jumping around inside the cabin where we would be.

http://www.thomson.ece.ufl.edu/lightning/

[Dimitri-2000X-Tampa]

I have one of those funny looking lightning diffusers on top of the mast. I wouldn't have bought it, but I inherited it from the previous owner...its a dealer option I believe. I couldn't answer any of the questions in the poll

Tampa is the lightning capital of the world, if I didn't go out except when there was no chance of CB's, I wouldn't get to sail at all from June until October. My weather is pretty much like Mikes, except that it is 30-40% chance each day. Stay away from that compression post.

[mgg4]

I guarantee that if I lived in the Gulf states, or the Midwest, or pretty much anywhere east of the Rockies, I would have a permanently installed lightning protection system. The protection system would involve a metal plate under the boat, probably in the area of the hull under the cockpit area, or just in front of the centerboard slot. This would be connected using a very heavy cable (probably at least 2/0 guage) to the mast. I'm not sure of the routing, but it would probably be through the compression post.

This permanent installation would provide the necessary lightning protection for me to sail in the 20-30% chance of thunderstorms that is normal for large parts of the country.

--Mark

[Tony D-26X_SusieQ]

Does anyone have any information on any Mac's being struck by lightning?

[Sloop John B]

Yeah, a guy up in New England had his Mac struck pier side when he was away. He came aboard to find water in the cabin, fuses blown out of the panel, all electronics shot. He had the boat surveyed to find there were many, many pin size holes in the hull. He thought at first he would have to scrap it but then had it repaired rather easily/inexpensively.

Maybe he still lurks.

I think with the compression post conductor, it's possible to have the hull blown out on one side or the other. That happened to a sailboat docked down here in FL. I think it was a small boat (19') with the mast coming through down to cabin bottom.

I've read everything I come across on the subject. I have been out in some horrendous storms here along the Gulf. After a very hot day they roll in low and loud from the sea. The flash and thunder are simultaneous, with just seconds between strikes.

I get the impression that if the strike enters the cabin, it will go for your water supply if it's low and close, like under the galley. Mindful, we're about 98% water. I wonder what that other 2% is? I curl up in the V berth, hold my hands over my ears and act unobtrusive.

My insurance company sent an expert over to verify that I had lost three large trees on the curtilage in one storm. The guy went back and informed them that two were from a single strike that also took out a neighbors huge live oak.

I got a lot of lightening stories, but yes, stifle that yawn!