What do you do to mitigate lighting damage?

[Basil]

These discussions are on going, having sailed in the Asia region for a number of years I have been in a large number of lightening storms etc, I have seen boats struck twice in the same event, boats with lightening boats protection devices, struck an major damage occurred. You don’t need to be struck to have damage as the charge in the air will cause all sorts of problems ( in my case alternator stopped charging, auto pilot failed, amp for radio system blew amounts may other items) an I was about 600 meters away from the strike.
As for insurance, in my experience (an I don’t want to generalise here) the insurance assessors in a number of cases I have been involved in have not been helpful. A further problem is that electrical item on board trend to break down suddenly for no reason months later.(after the claim has been settled).
One of the most interesting items was a generator which was running when the vessel was struck stopped in mid stroke, as the electrical side of the generator froze up. The owner an assessor were still arguing when I last heard.
In conclusion there is not much you can do.

[jen1722terry]

Yet another interesting thread on lightning.

Never thought of the jumper cable-shroud-water idea.

We cruise mostly in Maine and the Canadian Maritimes. Lightning is not the issue that it is further south, but we get some storms with pretty good fireworks.

Got me thinking: in marinas we use a corrision "fish," basically a 1 lb. piece of zinc on a piece of coated SS cable with a clip to the backstay. Would this function as lightning protection also?

We do carry jumper cables we could also use, but if the fish works, why not use it?

Cheers. Everyone stay healthy.

[Jannie Radiance]

I have a stainless steel 12mm chain attached to the cap shroud and overboard.

[chris mac]

Anytime there is a thunder storm close, I sing the thunder song from the movie Ted.
It's worked so far
[emoji106]
https://youtu.be/IEFt6BQuFJk

[garyfdl]

Originally Posted by Chris Cringle

two boats that sank. One because the exiting lightning blew out every bronze thru-hull on the boat

We had that happen a few years back in our marina to a boat in it's slip. No one witnessed the strike, and the 'good' news was there was only about 10" of water below the keel, so the boat just settled on the bottom. It was three days before a dock member noticed the boat low in the water and we got word to the owner. We patched the holes with Flexseal tape, pumped it out with a submersible sump pump, and were able to get it to the travel lift which was adjacent to the dock. Damage was relatively minor; radio survived, apparently because it was unplugged, alternator was fried along with some wiring, plywood floor covering the bilge was a little waterlogged, but most of the cabin sole was glass so not a big issue.

[Oceanride007]

https://www.youtube.com/watch?v=ww0XJUqFHXU

Bout Half way thru Walter Lewin expresses the clearest understanding of lightening that I have heard, and has a opinion of the use of lightening diffusers to limit the damage. This is good starting point.



Lightening diffuser first, lightening path second, oh apparently cats suffer worst in insurance claims due to the difficulty of getting water connection. But I also think we should all do more to protect ourselves from induced voltage. The build up of Current due to nearby lightening strike, or down the mast itself, to nearby wires like mast wiring and transducers is enormous enough to jump the gap in your switches, all electrics is made common thru the Negative wiring and potentially very expensive replacement. Perhaps we should invest in devices that would protect vulnerable wiring, perhaps only negative wires, also devices for TV and other Radio antenae. I have a switch to connect my battery negative to the Engine, should that be closed during a electrical event, I don't know, suspect yes, should I invest in quick disconnect devices, for my autopilot, inverter, mast wiring, think so but don't know for sure.

[BobFord]

There doesn't seem to be a clear cut answer to lightning strikes on boats. I am an all aluminium cat. First question - do I live in a 'Faraday Cage ' ? Second question - as a token effort ,I have a heavy copper rod , connected to mast base . This lowers in to water as needed. Will it do any good ? Over the years I have suffered 'field effect' , type strikes.
(2)Have only lost antennas and minor electricals. Comment welcomed.

[mvweebles]

Good article by Steve D'Antonio on lightning protection. My takeaway is you can improve your chances of surviving a lightning strike with a robust bonding system with heavy cable connecting the thru hulls.

https://www.proboat.com/2016/04/3530/

Peter

[skipmac]

Originally Posted by Jammer

All problems are not solvable


No lightning protection system is 100% effective


The goal is always to mitigate damage and improve the odds. In that light it is a tradeoff vis a vis upfront costs, weight, ongoing maintenance, and things like galvanic corrosion


You can ground the mast


You can put gas tube suppressors on the masthead antenna line. I use them at my house

Exactly correct. There is no way to guarantee you won't get struck or if you are that you won't suffer severe damage.

Grounding, bonding, etc might help, improve your odds slightly but at the end of the day, lightening is far, far more powerful than any preventive or mitigating technology available for a boat.

Google Martin Uman and read some of his technical articles. Took one of his classes in engineering school and the guy is brilliant. He designs protection systems for sensitive computer and electronic systems but to be effective they are large, complex and very expensive.

[Thumbs Up]

There used to be an extensive thread here with some experts. It was quite heated. No one could agree. I like to dock between two taller masts. The consensus is that if you install some type of protection system, it will be better than none. Lightning strikes come in many forms and are not all that well understood. Grounding the mast or rigging is supposed to lessen your chances of being struck by eliminating the static that the initial ionizing attachment strike is supposedly attracted to. I know of boats that were declared total losses because the hull itself was compromised. A good insurance policy might be the best protection.

[Suliwar]

When we encounter a thunderstorm at sea, to protect our handheld electronics we put them into our metal cooking pots and put the (metal) lid on top, creating thereby a Faraday-cage protection.

[skipmac]

Originally Posted by Thumbs Up

I like to dock between two taller masts.

I always thought this might help but a friend with a 26' Columbia was hit twice in three years and he was the smallest boat in the marina. Go figure.

Originally Posted by Thumbs Up

The consensus is that if you install some type of protection system, it will be better than none.

Pretty much what I've decided.

[flyingfin]

Saint Christopher statue

[Rucksta]

park between two cats

[j.g.evans]

I have had 2 boats struck by lightning. I have my insurance company on speed dial. Each boat had almost $30,000 in damage with just about everything electrical damaged. The insurance company was great.
In each strike I assume the lightning went down the mast and out through the keel. One boat was on land in storage in FL. The other boat was in the water in NJ. In each case everything on top of the mast was vaporized. There was no hull damage. I believe that most things electrical were damage by induced currents, but they were not so large as to melt the wiring. The voltage was high enough to char one instrument at the helm pedestal. By everything electrical I mean instruments, engine controls, pumps and even a trouble light was charred hanging in the middle of the cabin (I can't explain this.).

I believe the base of each mast was connected to the keels by wire buried in the fiberglass. I have now augmented the connection with heavy SS straps or bars. I wanted SS straps to SS keel bolts to avoid trouble.
Everything new is nice. Don't be aboard or stay wrapped in AL foil.