Sailing in thunderstorm

[duncan99210]

If you take a lightening strike to the boat, it's probable that it'll take out most electronic devices, switched on or not. That's because the energy in the strike will induce currents in the electronics high enough to burn out some components. Putting things in the oven may protect them but it's not a given.
There's also a good chance that it'll take out elements of the wiring system for the same reason. A friends boat was hit whilst ashore, everything turned off. The strike took out all of their electronics, much of the domestic and engine wiring and a couple of through hull fittings for good measure. That said, others have had near misses or lighter strikes that only took out some of the fixed electronics and left everything else undamaged. So, much seems to be down to luck as to the strength of the strike.
I seem to recall someone on here posting about taking a strike in the Solent: they were motoring at the time and the engine carried on working but most of the rest of the electrics and electronics on board were wiped out.
My drill for lightening is to avoid if possible, if not I'd shorten sail, sheet in the mainsail to minimise any damage a gybe might cause and start the engine: I'd then have power should we were to take a strike. And if time permitted and I remembered, put phones and the like in the oven.

 

[savageseadog]

I've sailed and set sail in a number of thunderstorms, it's never particularly worried me, we all have to die sometime and it's probably a quick death. I can't see any material difference between being onshore or offshore.

 

[mjcoon]

I've sailed and set sail in a number of thunderstorms, it's never particularly worried me, we all have to die sometime and it's probably a quick death. I can't see any material difference between being onshore or offshore.

Quick death not guaranteed! US states sometimes botch electrocutions...

Mike.

 

[KellysEye]

We were heading up to Bequia, Caribbean when we had a lighting strike about 25feet in front of us we had Elmos fire crackling in the rigging.

 

[savageseadog]

........... we had Elmos fire crackling in the rigging.

It would have been cool to light a ciggie on it

 

[Sticky Fingers]

Thanks for the comments and input. Long story short, we’ve decided on discretion ie stay put.

 

[BrianH]

I regularly anchor in the NE Italian lagoon complex, an area ringed by high mountains topped by cold air, with the warm Adriatic combining as a crucible of violent evening thunderstorms. I often view them spawning against the Alpine backdrop while watching the approach of vivid lightning strikes down to the lagoon waters, contemplating the situation of my mast as the highest point for miles around, connected via forestay, bow roller and chain to an anchor buried deep in mud - the perfect lightning conductor, with me somewhere in the middle of the chain.

I've never been struck and think that in all the momentous forces involved my circumstances would not be contributory in raising the risk significantly. This is since a friend on land in the marina boatyard was struck, which blew out all his electronics, melted some of his wiring and triggered his foredeck winch, under which he was sleeping at the time; he survived unscathed. And his steel-cradled Bavaria 40 was very close to a 50m latticed-steel VHF tower, suitably fitted with lightning-conductor, which was not struck, so the earth path seemed to be quite random.

So, I would not set out while a thunderstorm was approaching but would take little or no action while already at sea.

I do remember in my RAF aircrew signaller days being instructed to reel in the 150' trailing aerial in thunderstorm conditions and some years later, after having transferred to the RCAF, being hit by lightning in a Canadair North Star (Canadian-built DC-4 with Merlin engines), which damaged the electronics and some flight-deck instruments, but we landed in Montreal Dorval safely in good visibility.

 

[macd]

Yes or no? Would you go?

It depends where you are. The trouble with thunderstorms is that the winds are not only unpredictable in strength, as mentioned, but also in direction. So my preference when thunderstorms are forecast is a broad bay with shallow-sloping bottom and good holding. Even if some of the wind is onshore, it's rarely of sufficient duration to create large seas. (I might be less relaxed in such a location with lots of chain out and only a manual windlass -- or if the same bay was at all crowded with other boats.)

If in a harbour stern-too with lots of similar company, I'd seriously consider putting to sea. Lots of yachts were damaged over several days of thunderstorms in Greece a couple of years ago, many because their neighbours clattered into them. On marina pontoons, the danger would probably be much less.

This site, which offers real-time lightning monitoring, is invaluable: http://en.blitzortung.org/live_lightning_maps.php?map=10
(There are links on the page to larger-scale regional maps.)
It can't, unfortunately, predict wind strength within lightning squalls, just whether storm cells are active and, if viewed over a period, the direction they're moving.

'CAPE' data, which some grib viewers can download and display, is a useful measure of vertical instability in the atmosphere, which is strongly associated with thunderstorm activity.

 

[capnsensible]

Thanks for the comments and input. Long story short, we’ve decided on discretion ie stay put.

Smart move I reckon. :encouragement: Or actually, not move!

 

[sailaboutvic]

A season sailing in Croatia will take away more of your fear of thunder storm or scare you so much you won't go near your boat if a thunder storm are forecasted ,
In 40 years of sailing I not experience the type of thunder storm we had there with violet wind coming in second ,
I can understand why Rupert wrote what he did , we too now aren't that bothered when they are forecaster but get perpair for what may happen .

 

[mjcoon]

A season sailing in Croatia will take away more of your fear of thunder storm or scare you so much you won't go near your boat if a thunder storm are forecasted ,
In 40 years of sailing I not experience the type of thunder storm we had there with violet wind coming in second ,

I remember a storm there with purple sky!

Mike.

 

[Lon nan Gruagach]

Interesting responses from those that have really been there. A remarkably different story from what I would predict.

TV transmitters require regular maintenance to replace the bit that are chewed out by lightning strikes. It seems from the experiences here that that isn't an issue with saily boats.

I'll leave you to wonder what damage might have occurred here...

 

[Roberto]

Interesting responses from those that have really been there. A remarkably different story from what I would predict.

TV transmitters require regular maintenance to replace the bit that are chewed out by lightning strikes. It seems from the experiences here that that isn't an issue with saily boats.

'

we were hit once, on a night crossing from then Yugoslavia to Italy: big blinding flash, as vision came back there were pieces of fire falling from the mast top (the vhf antenna), the radio was fried. It was in pre-gps days so no other electronics, I remember the compass began turning round and round, we eventually managed to land 10miles from where we were heading so not bad
The mast step was connected to a keel bolt, its insulation was found melted. We had two persons sleeping on the floor just beside the mast and they were unharmed. We were motoring, the engine kept on turning.

 

[Sybarite]

My discriminant is with/without lightning: my worst sailing experience is feeling totally helpless among lightnings falling all around, real nightmare

My worst was on our first trip to Scilly - the worst thunder storm since Congo days.

My sister was in the forepeak with two sleeping bags over her head and she could still see the light.

I keep a chain which I attach around the mast and then lead it overboard and into the water. Whether it helps or not at least I feel that I have done something.

 

[dragonvc]

My worst trip in a thunderstorm was Camaret to Falmouth thunder and lightening most of the trip with heavy rain,most impressive was the multiple lightening strikes into the water probably in excess of 120 but we were not struck.Not too worried about mast or rigging strike as quite effective faraday cage but do not hold rigging.Two other occasions ,first on passage Hamble to Dartmouth other yachts in the area one of them struck and electrics taken out,second was arriving in Roscoff from L'Aberwrach to find a yacht moored with all electrics destroyed in overnight storm.Talking to a friend who had seen a YW dayboat struck and went to ground through the mast step and water came in but I think these are wood boats.I do have a great respect for lightening having seen horses and cattle killed usually on hillsides often close to metal fences,the worst was 6 heifers killed under a tree with a six inch rent in the bark despite the tree being in the bottom of a valley.Would I set off into thunderstorm probably not but if caught out in one I would be prepared to reef quickly.

 

[Mark-1]

Been posted many times on YBW but below is a podcast featuring Dr. Ewen Thomson - who specializes in lightning and its effects on boats. AFAIK this podcast is as close as we're going to get to a definitive source on this right now:

http://furledsails.com/article.php3?article=676

 

[BurnitBlue]

When I was anchored just south of Miami, the boat next to me was hit by direct strike. A strip about six inches wide was torn from the starboard hull from the shroud to the waterline. It was a catamaran like mine and it started to list quite quickly. We were anchored close to the beach. Nobody aboard at that time so I and a few others managed to get the anchor up and beach the boat.