We purchased a Hunter 38 last year and on our Maiden voyage we were struck by lighting on Lake Erie The strike hit the mast and exited in multiple points in the hull, rudder, keel. We totaled 24 hull holes ranging in size from 50 cal sized to bazooka sized. We were not hurt and the boat was fixable (we hope). Do you have any wisdom on how to make a sail boat a less attractive "lighting rod"?
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Relston—
I am guessing that you didn't have a lightning grounding system on the boat. There are basically two schools of thought when it comes to lightning and boats.
The first school is that you bond the major metal elements of the boat together using heavy wire, and give the lightning as direct a path down to the water as possible. This, in theory, will create as simple a path for the lightning to travel, and not cause it to side flash. The side-flashes are what caused all the holes in your boat—and was the result of the lightning finding its own shortest paths to ground. In theory, this will protect the occupants, by creating a faraday cage of the stays, shrouds, mast, and rails. In theory, it will also help prevent side flashes. However, doing so will make the boat somewhat more likely to get hit by lightning.
The second school of thought on lightning, is to not bond the mast to the water. The idea here is that the boat will be less likely to be hit by lightning, since it isn't as good a ground as a bonded boat would be. However, the chances of serious damage, in the case of a lightning strike, are far greater, as you experienced.
The trade off is basically less severe damage and a slightly increased risk of being hit versus a greater risk of severe damage and a slightly lower chance of being hit.
I am guessing that you didn't have a lightning grounding system on the boat. There are basically two schools of thought when it comes to lightning and boats.
The first school is that you bond the major metal elements of the boat together using heavy wire, and give the lightning as direct a path down to the water as possible. This, in theory, will create as simple a path for the lightning to travel, and not cause it to side flash. The side-flashes are what caused all the holes in your boat—and was the result of the lightning finding its own shortest paths to ground. In theory, this will protect the occupants, by creating a faraday cage of the stays, shrouds, mast, and rails. In theory, it will also help prevent side flashes. However, doing so will make the boat somewhat more likely to get hit by lightning.
The second school of thought on lightning, is to not bond the mast to the water. The idea here is that the boat will be less likely to be hit by lightning, since it isn't as good a ground as a bonded boat would be. However, the chances of serious damage, in the case of a lightning strike, are far greater, as you experienced.
The trade off is basically less severe damage and a slightly increased risk of being hit versus a greater risk of severe damage and a slightly lower chance of being hit.
Personally I signed up for 'dog's second option. My boat was on Lake Erie from 1979 until 2007. It never experienced a lightning strike. And it was never wire bonded.
Now I wonder what that will do to my luck here in Florida?!
Now I wonder what that will do to my luck here in Florida?!
If I recall, this is a new boat, both chainplates and mast / compression post have ground wires run tot he keel bolts. My H33 is set up that way.
It so happens I spent a lot of time with probably the most reknown expert on lighting strikes on boats. In the end he says lighting will do what it wants to do regardless but you can reduce the possibilities. He designed a grounding system that has a very clever contact that is fitted through the hull. I googled and couldn't find anything on him. He was going to market the product but I haven't talked to him for a while. I don't have his number. He was a professor at the University of Florida. (Go Gators). That was rotten luck getting hit like that. I hope nobody was hurt.
If it had heavy lightning bonding wires between the chainplates, mast and keel bolts, I'm a bit at a loss to explain why it would have side-flashed so badly and in so many places.
I know that both the new Hunter 27 and 33 that I have been on have been bonded from both the chainplates and the compression post to tha keel.
Fresh water could have been some of the explanation for the extent of the damage. The Hunter 27 I mentioned was struck by lightning in a fresh water lake, and the damage was similar to the OP's description.
Glenn—
I believe you're talking about Dr. Ewen Thompson. He does have a company that produces the lightning grounding system you're likely mentioning. Their website is located HERE.
The product looks like this:
I believe you're talking about Dr. Ewen Thompson. He does have a company that produces the lightning grounding system you're likely mentioning. Their website is located HERE.
The product looks like this:
" Lighting never strikes twice in the same place " so not to worry ! ! OK we know that is not true but after one hit the odds got to be in your favor ! ! Here is my thought/concern. I question fixing a hull with that many holes, as you said may be fixable(hope ?). I would push (hope)for the insurance company to total out the boat. Even if the boat is repaired as "new" you still have a repaired boat. This will impact your resale when you go to sell. Plus you will have are long time with out a boat for the repairs and may want to ask Hunter if the hull warranty is still good after the boat being hit by lightning. Don't mean to bring you down but better to get this out of the way now rather then later. I would also get a survey done after the repairs (make it part of your settlement with the insurance settlement) got to think there may be other damage as well, electrical systems etc, etc, most navigation equipment is very susceptible to lightning damage as are gauges and so on. My big concern is I am guessing that Hunter will not honor a hull warranty, I don't blame them, unless the factory does the repair on the hull as yours has had extensive damage. A 50 cal is a big hole but you said bazooka sized ! And you have 24 holes in rudder, keel and hull ? ? Keep asking your self would you buy the boat after it had been repaired ? ? Glad no one was hurt ! Keep us posted and Good Luck !
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Sailingdog,
That is the product Dr. Thompson developed. Ewen explained to me that though you may be totally bonded the amount of energy can be too great and bypass the grounding system. It is too much energy. His product reduces the resistance at the hull water transition area that creates additional ohms. It is a bottleneck so to speak. He seems to be a very smart guy and has done a lot of research and testing.
That is the product Dr. Thompson developed. Ewen explained to me that though you may be totally bonded the amount of energy can be too great and bypass the grounding system. It is too much energy. His product reduces the resistance at the hull water transition area that creates additional ohms. It is a bottleneck so to speak. He seems to be a very smart guy and has done a lot of research and testing.
Lightning will strike where it will.
The forces of lightning are so great you cannot harness them in a small boat whatever you do. From now on the odds are in your favor, as they always were.
The forces of lightning are so great you cannot harness them in a small boat whatever you do. From now on the odds are in your favor, as they always were.
Fresh versus Salt water is a difference... Fresh is not a good conductor - Salt Water is much better...
If lightening DOES hit your boat..... then a GROUNDING system will minimize the side flash... If one of those 50 caliber holes was in you....
SO you do your best - and get off the water if you can avoid a storm.. Most lightning is not the "superbolt" kind...
-- hope all are OK and that you were insured... !!!!!
--jerry
If lightening DOES hit your boat..... then a GROUNDING system will minimize the side flash... If one of those 50 caliber holes was in you....
SO you do your best - and get off the water if you can avoid a storm.. Most lightning is not the "superbolt" kind...
-- hope all are OK and that you were insured... !!!!!
--jerry
I'm going by foggy memory from sometime last season, but there is a green heavy guage wire from the keel bolts to the compression post and at least two more going in the direction of the chain plates, although I can't recall if I traced them to the chainplates or not. I might have assumed that's where they were heading, just one of those things that you see while doing other work and tuck it away into the hhmmmm memory.
Scott, you are correct about the green heavy gauge wires. Our 2005 38 has them too. There will be one to the arch also. They are to prevent "sideflashes" between the mast and chainplates during a strike. Lightning will travel miles in the air, a few feet inside a boat is no big deal. Unfortunately some of the links on Ewen Thompson's site are broken because he has some excellent information on this subject. I became intensely curious after our last boat was hit. I had always assumed that we would be safe in the cone of protection from the rig. We were not hurt but later found that a "sideflash" had come from the mast through the cabin, through metal cans in a locker and out the side of the hull on the waterline!
You might be right John. I wonder if there are lightning strike statistics comparing keel-stepped to deck-stepped? Still say it pays to get a slip next to a taller mast. Notice in my avatar how much higher the H380 boom is right next to me.
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