Lightning strikes

[davierobb]

There has been a lot of discussion on the YouTube channel following on from this video about lightning protection on boats. Seems to be a really contentious area. I'm of the opinion that its mostly down to luck and and not being in the wrong place. There are loads of sailors stuck in parts of the world at the wrong (weather/season) time due the covjd restrictions, not an easy time to be a world cruiser.

Has anyone installed electronics with lightning protection in mind or lightning protection systems?

 

[coopec]

Yes, I have installed lightning protection on my yacht.

You probably don't have to worry about a lightning strike in Scotland but if you were in Florida (for instance) yachts can expect to get hit twice in their lifetime. Look at the global map showing incidence of lightning strikes:

World Lightning Strikes Map

Here is a map showing where the thunderstorms are right now. If you look over near Turkey you'll see a thunderstorm and the flashes. Normally there are thunderstorms all over Europe but right now it is very quiet.

Real Time Lightning Map

 

[coopec]

Yacht lightning strikes: Why they cause so much damage and how to protect against them
Both UK and US-based insurers also report that multihulls are two to three times more likely to be struck by lightning than monohulls, due to the increased surface area and the lack of a keel causing difficulties with adequate grounding

Why lightning strikes cause so much damage and how to protect against them

 

[vyv_cox]

Article coming up in PBO in a month or so. A case history about a strike and a couple more contributions.

 

[Graham376]

Ours isn't protected. Advice is mixed but we follow the thought that a protected boat is more likely to be struck but suffer less damage whereas an unprotected one is less likely to be hit but more damage. We had multiple lightening strikes pretty close to us during one violent storm, maybe 50 metres away, into the water between moored boats but none were hit and I can't understand why. I found it very scary at the time.

Renewal letter from Y Yacht stated that insurance losses in the Med were in part due to increased number of claims for lightening strikes. Experts say as temperatures rise, thunder storms will become more common.

 

[PabloPicasso]

There has been a lot of discussion on the YouTube channel following on from this video about lightning protection on boats. Seems to be a really contentious area. I'm of the opinion that its mostly down to luck and and not being in the wrong place. There are loads of sailors stuck in parts of the world at the wrong (weather/season) time due the covjd restrictions, not an easy time to be a world cruiser.

Has anyone installed electronics with lightning protection in mind or lightning protection systems?

Anyone got a link to part 2?

 

[catlotion]

There's more here. Go to about 47 minutes in...

 

[William_H]

Ours isn't protected. Advice is mixed but we follow the thought that a protected boat is more likely to be struck but suffer less damage whereas an unprotected one is less likely to be hit but more damage. We had multiple lightening strikes pretty close to us during one violent storm, maybe 50 metres away, into the water between moored boats but none were hit and I can't understand why. I found it very scary at the time.

Renewal letter from Y Yacht stated that insurance losses in the Med were in part due to increased number of claims for lightening strikes. Experts say as temperatures rise, thunder storms will become more common.

I would disagree with the statement that a protected boat is more likely to be struck. Graham is assuming that a low resistance from water to mast top is more likely to encourage the leader ionisation that goes up to bring the strike down. I think in fact that a high resistance from ali mast to water via wet bilge or wet hull will be enough to set off the leader just as well as a low resistance. (ie protected) Certainly it is a well established practice to provide a low resistance path for tall buildings. ie a lightning conductor of heavy current carrying capability from top to ground. Re electronics disconnect all wiring from device when lightning is around as the first and likely most useful step to protect it. ol'will

 

[coopec]

Ours isn't protected. Advice is mixed but we follow the thought that a protected boat is more likely to be struck but suffer less damage whereas an unprotected one is less likely to be hit but more damage. We had multiple lightening strikes pretty close to us during one violent storm, maybe 50 metres away, into the water between moored boats but none were hit and I can't understand why. I found it very scary at the time.

Renewal letter from Y Yacht stated that insurance losses in the Med were in part due to increased number of claims for lightening strikes. Experts say as temperatures rise, thunder storms will become more common.

I won't wear the thought that a protected boat is more likely to be struck. I'm sure it is the luck of the draw.

My Sister has friends who were fishing 50km out to sea off the West Aust coast when out of the blue they were hit by lightning. One guy was sprayed with molten plastic off the instrument panel and all electrics were dead: nothing they could do but drift. Fortunately the crew of a boat on the horizon saw them get hit and came to their assistance.

 

[davierobb]

Anyone got a link to part 2?

If you open YouTube and search for sailing into freedom then you'll get his YouTube channel. If you subscribe then you'll get the new episodes. He usually releases on per week, no cost to watch.
There's another channel parley revival who are also in Panama ish and they have also had a strike. Strangely the strike is not their biggest issue,the cats falling apart.

 

[Plymsea]

If you open YouTube and search for sailing into freedom then you'll get his YouTube channel. If you subscribe then you'll get the new episodes. He usually releases on per week, no cost to watch.

Part 2 is not out yet, but please do watch this guy's video(s)...

Sorry to slightly drift the thread, but he has been making videos for years and during this time he has sunk a cat, been exiled by Covid-struck nations for 71 days and here most recently lost almost all of his electrics/electronics from the lightening.

If having watched it you feel inclined to share it on social media I know he will appreciate it, the more people watch the more ad revenue he gets.

To make matters worse he is away from his wife until such time as he gets the boat back in the water and sailing again, so he can go and pick her up.

 

[William_H]

Ours isn't protected. Advice is mixed but we follow the thought that a protected boat is more likely to be struck but suffer less damage whereas an unprotected one is less likely to be hit but more damage. We had multiple lightening strikes pretty close to us during one violent storm, maybe 50 metres away, into the water between moored boats but none were hit and I can't understand why. I found it very scary at the time.

Renewal letter from Y Yacht stated that insurance losses in the Med were in part due to increased number of claims for lightening strikes. Experts say as temperatures rise, thunder storms will become more common.

My theory is that you have an area of high static voltage in the sky at a particular point. This will look to the closest point on earth (sea) to discharge to. Usually just below the point of static charge but it will go sideways if there is a mast sticking up into the sky which will make the path less distance even if it has to go sideways.
So a 50 ft mast might be the preferred hit point over the circle of water perhaps radius 3 times the mast height. But this of course geometrically speaking depends on the height of the static build up. (cloud) But then lightning strike seems to be so variable my theory might not help much but I think it could explain why lightning will go to the water seemingly close to the boat without hitting the mast. ol'will

 

[179580]

Good article in one of the mags a few years ago by someone who got zapped, Multihull, China Sea I think. Guy was an Aeronautical Engineer.

 

[coopec]

Good article in one of the mags a few years ago by someone who got zapped, Multihull, China Sea I think. Guy was an Aeronautical Engineer.

Is this the article?
Lightning: why we were struck - Yachting Monthly

 

[179580]

Is this the article?
Lightning: why we were struck - Yachting Monthly

Yep.

 

[Plymsea]

So a 50 ft mast might be the preferred hit point over the circle of water perhaps radius 3 times the mast height.

Trouble is, I suspect a lightening strike that close will still do EMF damage to boat systems. Does grounding even help mitigate that?

 

[Graham_Wright]

I wonder if a copper coated hull makes any difference - positive or negative.

 

[coopec]

I wonder if a copper coated hull makes any difference - positive or negative.

I don't think steel yachts have any trouble?

I'm sure I've read that ships get struck all the time but it doesn't worry them.

A ship siphoning oil in the Gulf of Mexico was struck by lightning. What are the odds?

 

[Alex_Blackwood]

I'm sure I've read that ships get struck all the time but it doesn't worry them.

It does shake you about a bit! And makes a bang!

 

[ProDave]

We were caught in a violent lightening storm this year. In the Moray firth.

We had been for a day sail, and the wind had died, So motoring back, we saw this big black cloud in the distance but not in our path.

That soon changed very quickly and it was clear we could not avoid it. So I put on the oilies and hunkered down. Very frightening in torrential rain, very poor visibility and lightning striking all around us.

I really did not know what to do. I could have stopped and hunkered down in the cabin with SWMBO, at least I would have been dry. But would I have been any safer? In a small plastic boat, if the mast did get struck, would hanging onto a wooden tiller close to the back stay be safer or less safe than being in the cabin close to the wooden mast post at the foot of the mast?

I suspect by motoring I may have slightly reduced our time in the storm.

I did wonder if I should have wrapped the anchor chain a couple of turns round the bottom of the mast and dropped it into the water to give a better ground path. Would that have improved the chance of less catastrophic damage? Would that have increased or reduced the chance of a strike?