Sailing in thunder storms.

Allan

Allan

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I'm planning to sail from Friday morning until Saturday night and have just seen they are forcasting thunderstorms. I have a metal box onboard, in which I will put my handheld GPS, VHF and phones etc. Is there anything else I should do if I see a thunder storm approaching?
Allan
 
Some storms pack wind, some don't but it's prudent to shorten sail in anticipation.
Best to put crew below with instructions not to hold onto anything metal. Smile encouragingly at the helmsperson from the safety of the companionway. SWMBO always appreciates it when I do this.
 
Good point, in the past I have become a bit mesmerised by weather approaching and not been ready when it arrived. The thunder is, at present, forcast for during the day, when I will be sailing alone.
Allan
 
Shorten sail, then, if it's a long trip, get the shower gel out !

Did this on one trip, just came off watch, not smelling too good, had a dam good clean in the torrential rain. Rest of the crew thought I was nuts.

But as I pointed out to them, I now smell better than you lot & if I am going to die, so be it, gotta go sometime ......
 
I think I'd unplug the wind display (if you have one) as the last thunderstorm near my boat - just a couple of loud claps and one flash of lightning - took out my ST60 display head. /forums/images/graemlins/frown.gif

Had to fork out a small fortune for a new ST60+ /forums/images/graemlins/frown.gif

I'm definitely unplugging mine when I'm anywhere NEAR a thunderstorm in future!!
 
I can't unplug the wind instrument but I could disconnect the VHF aerial, I wonder if that is worth doing? All other eletronics, including radar and chartplotter are difficult to get at. I'm now wondering if it is worth turning everything off?
Allan
 
Yes, as Sailorman says, it makes no difference. You have to remove electronics and put them in a metal box - I use the oven.
Just a close strike can take out the 'chips' in electronic devices.
 
Over is ideal...ensure hand held VHF AND GPS are inside.

ps. don't forget them!

I remember 4 years ago was sailing in the solent in the biggest ever storm, knocked out my electrics.
Everytime i heard a thunder clap, I would take my hands of my stainless steel wheel, totally pointless, but still do.
It's when you start "ducking" after every clap you start to [--word removed--] yourself.
 
I think I will stick with what I have. Looks like there is nothing I can do but trust to luck! Is lightning damage covered by insurance?
Allan
 
I hate them and we have had a lot in the last few weeks cruising the east coast USA. Current drill is everyone below and away from metal. Gas off at bottle, VHF antenna unplugged, hand held GPS, VHF and cell phones in the oven, non essentials switched off, heavy duty jumper cable attached to shroud and other end in the sea, rubber soled footwear in the cockpit and no touching metal.
 
I have to admit to something that obviously some are going to say - IDIOT !

I do nothing if I get caught in one, apart from make all stay below except myself.
Having seen effects of a lightning strike on a ship in West Africa - I reckon you could do all you want - but still you are going to fry so much. To the poster in USA who puts a jumper lead from stays to water ... sorry but you'd need a cable as big as your boat to carry that load if you got struck. The lead you have even if welders cable would only light up like a bulb filament. Disconnected equipment would still be frazzled if boat hit by the electromagnetic and sheer power of the strike.

The ship in West Africa - we were on the buoys in Port Harcourt, Nigeria discharging Bitumen. Wives were all standing at stbd midships accommodation rail ... when all of a sudden the whole ship was lit up like a pyrotechnic display ... wives hair stood up and had a frizzy set ... antena's were smoking on the masts ..... electrics, lights, all sorts went on and then off ... it was like a bunch of kids playing with the switches but at incredible speed !

Casualty ? Sailor VHF set. An old one with separate control box mounted on bridge aft bulkhead. The circuit boards inside being bakelite melted and there was a run of molten plastic out the bottom vent and down the bulkhead ...
We went up mast to check antena arrays ... all were fine except for the VHF antena. This was a later GRP style - having been replaced not long before. It had a perfect burnt hole in it through to the conductor inside. The cable leading down was a brittle fried mess .... the white paint of the mast was fried around the cable where it was clipped in place.

It was then that I was told by Sparky and Electrical guy that came from shore to repair gear ... no matter what you do - lightning is so powerful that you have little chance of saving anything if it really wants to hit !! After that strike - I believe them.
 
We need Foxy to tell the story of when he was struck by lightning. Hair raisng stuff, just in the listening.

Anyway, there is a point to earthing the mast but it is quite right that it cannot possibly conduct a lightening strike.

Its the same theory as lightning conductors on churches, their name is misleading.

The top of a structure will gain a small static potential (voltage) if it is not earthed. Thus if the lightning is due to strike the boat (or spire) OR a point near it, the charge will attract the strike - its not that the high point is nearer the clouds it is that it has a small charge. Earth the top of your mast and tha charge disappears, and the mast is now no more likely to be struck than the bit of water next to it. As it is now a small target your chances of being struck are much reduced.

Would I trust the theory? Not after hearing foxy's story, I'd stay in port.
However if I was stuck out in a sailing boat I would earth the shrouds.
 
I agree, that's the theory.
Actually the rig on most boats is already earthed via the keel and bonding system. I don't know if an extra earthing strap from shrouds to the sea will have any effect and, as you say, it won't conduct a lightning strike safely away to the sea.
When we were hit the masthead instruments were vapourised but the vhf antenna was not, and every single electronic device, from radios to depth sounder, was damaged. To make matters worse the alternator charge regulator burst into flames, setting the engine compartment on fire. Oh joy!
The wooden masts were unscathed as were all deck fittings, through hulls and chain plates.
The lesson is that the effects of a lightning strike are completely unpredictable and, once you have seen one close up, you realise that any defence involving hanging bits of wire here and there or fitting bottle brushes to the masthead is futile. The power of the strike is unimaginable!
 
I don't discount the methods used by people to try and lessen the effects of a near or on strike .. What I do feel is that some are guilty of mans inability to accept that Mother Nature is awesome and can beat whatever man does any day it wants. Lightning is one of those Nature items that man cannot defeat - it is just so powerful at times. Anyone who has seen it in the tropics, the average in UK / temperate climes is nothing when you see the carnage and power of the West African / Carribean strike ... Singapore etc.
Having seen many that are not so near, and near - that you feel the hair rise, the skin tingle ... the smell of ozone ... Wow if that was a hit ??
 
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