Electrical storms on the Gulf of Mexico

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Jun 13, 2005
74
Hunter 30_74-83 Fowl River, AL
Electrical storms on the northern gulf coast are an almost-everyday occurence. Is there something I should do, or not do, for protection from lightning, other than trying to avoid these storms? I sail a Hunter 30 with a 42-foot mast, so I expect I will be a large target for lightning.
 
Feb 26, 2004
23,320
Catalina 34 224 Maple Bay, BC, Canada
READ

Good question, many answers. Some believe that they should do everything possible mechanically and electrically, others say, if it hits me I'm toast so why bother with the expense. Do some Forum Archive searches on lightning, lightning protection, dissapators, ions, etc. And the do some research on your own, like through Google and books. It's such a "heavy" and subjective issue, that this forum isn't likely to add much to the tremendous volume of technical literature out there already. Finally, your boat, your choice. Stu
 
Jun 2, 2004
3,648
Hunter 23.5 Fort Walton Yacht Club, Florida
Clean Living

Even if you bought everything out there and installed it on your boat you could get hit. If you get hit it might destroy your boat and kill you or just blow out a couple of bulbs andsoil your drawers. More folks are killed on the golf course than boats by lightning so my plan is to do right by everyone and everything and stay off the golf course as much as possible.
 
T

Tim Welsh

Here's a good link on lighning and boats

Someone else had this link on here a while back
 
Jun 3, 2005
20
- - Sunshine Coast
lightnin'

the trouble is with lightening and glass and timber boats, is that no matter what you do, you can only hope and prey Lightening is very random, the voltage is so high that it will not track where you try track it, if you try ground chainplates to keel round and under the deck the lightening will just not follow that route It CAN just head stright to a skin fitting and blow that fitting off the only way is a metal boat, even with metal, you usually lose all electronics, good idea to disconnect your ssb tuner, and if possible take the juice off the board, usually at sea there is time, to do all this the first time one gets hit by lightning is darned scary, I was bombed over and over in Momi Bay Fiji, lost the ssb, , we had a steel yacht. can member these fijians in a canoe took shelter alongside Now I just go below and read a book, its always awesome the power of nature
 
Jun 1, 2004
227
Beneteau 393 Newport
Only God can predict where lightning will hit.

Several years ago we were in Montauk during a severe thunderstorm. We were tied to a dock about 8 feet away from a large sport fisher with the standard outriggers. My mast was many feet higher than his outriggers and he was hit by lightning. He had everything in the boat bonded and the entire electrical system including all the instruments were fried to a crisp. That much power cannot be redirected by any means. Jim
 
R

Rick I

Pray

Got hit while at sea a few years ago. Everything blew,all electronics, alternator, lights etc. luckily no holes. When we hauled the boat for inspection later there was "treeing" (burn marks) at ALL the through hulls, also at the pintle and gudgeon, wherever there was a metal fitting. None of the through hulls were bonded which goes to show that the charge is so great it just goes right through the boat. Scared the hell out of me. There is nothing to stop you getting hit except prayer, that's what I do now. So far so good. :)
 
A

a poor old sailor

Insulate, don't ground!

Lighting is the result of a positive and negative charge building and building to the point of a sudden (and sometimes catastrophic) relief. I think it's negative in the cloud and positive on the ground/water, but I could be wrong. So, ya got this thunderboomer above you that is developing quite a charge. This charge is attracting an opposite charge on the ground/water below. Then you come along with yer mast and wires and keel connected to the water...well, where's the charge gonna go? It gets concentrated at the top of your little metal stick. The charge builds and builds until WHAM, lightning just got you. Hopefully, it followed yer little wires to the keel and didn't hole yer boat, but the resulting EMFs have fried all yer 'lectronics anyways. But, as is usually the case, the lightning is way too powerful to stay on yer little grounding path and is just as likely to jump from a shroud to the water...or it may go right through the hull. Thus putting you at nearly exactly the same risk as me of being sunk by lightning, but I have a bit better chance of not getting hit because I didn't provide a nice easy path for the charge to concentrate at the tip of my mast. So please, ground yer boats - I'll anchor next to you for protection...
 
F

Franklin

interesting

If what you say is true, then that would suggest that Hunter actually got it backwards. They ground the mast and shrouds BUT NOT then thru hulls. One of my tasks this weekend is to ground my thru hulls.
 
Jun 4, 2004
629
Sailboat - 48N x 89W
insulation is impossible !

“a poor old sailor” suggests that you insulate (instead of grounding). Considering that a typical lightning bolt may have traveled through about 6 miles of air (an excellent insulator) to get to your mast (whatever) - I’d repeat “Jack’s” question - how do you think you can insulate yourself from lightning? I know of NO lightning expert who would suggest insulation over bonding! See “Tim’s” link to “Lightning & Boats”. FWIW, Gord
 
A

a poor old sailor

"Insulate" was tongue in cheek

I did not mean that you should try to create too much resistance for the lightning to get through your boat - that would be utterly impossible! What I meant was to lesson the electrical connection between your mast and the water such that the building charge cannot easily migrate from the water to the tip of the mast, making your mast a much likelier place for the lightning to hit when it does strike. I have seen no evidence that shows that grounding prevents damage. Lightning is so powerful that little grounding wires are relatively meaningless, especially if you put a bend in them. Lightning just doesn't typically follow that path, but that path may increase your chances of getting hit. What it comes down to, and what others have said, is that in the face of lightning....PRAY
 
Dec 2, 2003
4,245
- - Seabeck WA
OK Old Sailor, here's some evidence. Me.

With Hunters' stock grounding system our mast was grounded to the iron keel. The base plate was connected with #8 wire to the keel. In many electrical storms in the tropics, we were never hit. One time we were dingying back to our boat with friends when a massive storm blasted the fish out of the water in the anchorage. No one got hit. Why we survived in that rubber boat, I've yet to understand. Aboard a sailboat the crew is safe under the 'Cone of Protection' that extends out around the mast. Stay in that cone and you won't be hit. Correct me if I'm wrong here gang, but no one on a sailboat has ever been hit by lightening. Many power boaters die each year from lightening. Anyway, later during a haul-out in Costa Rica I asked a friend for advice dealing with iron keel corrosion. He said to seal it up with polyurethane. Great! I did. And I installed one of those Forespar lightening ground rods. The kind with the funny wires sticking out of it seen in the picture. Off I went for the Panama Canal. We just got out of the anchorage when a rain squall moved in front of us on radar. I was worried about lightening but didn't hear anything. The squall was lessening. Then all of a sudden, BAM! The masthead showered debris down on the deck. The sound was louder than dynamite. All of the electronics blinked off. I'll spare the details. The point is, even with that new lightening rod, we got hit. What was happening in the natural world? Was this random? No other lightening had even gone off! But this charge came to us. Why? After months of study and over $15K of uninsured repairs, I learned the following; Sealing up the keel disabled our lightening ground. The return wave was not grounded anymore so 'St Elmo's Fire' told the charge above that was forming, to HIT ME HERE! It did! Blew out over 300 holes in the epoxy keel cover. We made it to Florida and I made repairs. One of the things I did was to bypass the keel and install a ground plate. That took care of future strikes. We haven't been hit since. The keel isn't even hooked up. The Forespar rod is still there. It is wired with a jumper to the shrouds that are wired to the ground plate. All paint is bypassed in this manor insuring good electrical grounding of the RETURN WAVE. When grounding our boats, we are grounding the return wave, NOT THE LIGHTENING BOLT. No return wave, no lightening bolt. But hey!,,I could be wrong! I only speak from months of study and experience with the real thing. If it were that easy no one would ever get hit. Right? Oh, note in the picture that the wires extending out of the ground rod are bent and funny looking. That's from the strike. They refuse to straighten.
 
D

dbecker68

Quite a range of opinions

*o OK, I see that there is not a "correct" answer to my question. I have been, and will continue, praying. I think I understand that the boat is already grounded, and I guess that's about as good as you can do.
 
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