WNS: What Now Skip (March) -- When lightning strikes

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Thank you to everyone who contributed to last month's WNS. In terms of your response, it was one of the most successful WNSs that we've ever had, generating over 20,000 words of replies. If we could have used them all it would have been more than enough to fill a book of 80-odd pages, or about half the total editorial content of a typical issue of Motor Boat and Yachting. Unfortunately, that ain't the way it works, and I somehow had to edit it all down to just over 1000 words. I hope I did you all justice in the few words I was able to keep. My apologies to those who didn't make it into print, and my special thanks to those who did.

Now, back to business as usual....

* The idea of WNS is to offer a nautical puzzle, which experienced skippers will (hopefully) find interesting or entertaining, from which the less experienced may be able to learn something, and from which we can all pick up ideas.
* The WNS skipper is a fictional character. Any resemblance to a real individual is purely accidental, except that he occasionally makes mistakes, and he is not able to make time run backwards. So having got into a situation, he can't get out of it by wishing that he had done something different.
* WNS is not a competition to see who can match some hidden but predetermined solution. Of course I have an answer in mind (you wouldn't like it if I gave you an impossible situation, would you?) But mine may not be the best or only answer.
* If you think I've missed something or given confusing information please ask for clarification.
* Attributed extracts from selected posts will appear in the March issue of MBY.

Our hero has been out for the day in a mate's 24-foot Boston Whaler -- a fast, rigid open boat, with a canvas bimini casting welcome shade over the helm and front passenger seats. But as the two men headed back to the harbour, they saw a thick black wall of cloud rolling in from the west. By the time they reached the Fairway buoy, the wind had increased dramatically, whipping a stinging spray from the wave-tops, while huge, heavy raindrops hissing down into the sea, cutting the visibility to a few hundred yards. At reduced speed, they head on towards the harbour, uncomfortably aware that the thunder was no longer an occasional distant rumble, but was now a series of distinct cracks -- and that each crack was following so soon after the lightning that they were sure the storm was almost directly overhead.

The boat's mooring is little more than a mile away, and there's a marina even closer. But does it make sense to pick up a wet, steel chain, perfectly earthed in sea water, in the midst of an electrical storm? Or to venture amongst a mass of sailing yachts. Or would it be better to head back out to sea? What now skip....?
Click to expand...
 
I honestly don't know, havent studied lightning, so I'll be interested to hear if others know this subject well. Off the cuff I'd say the following, and I'm assuming it is the worst sort of forked lightning

1. Remove/fold down any upward pointing pointy objects like VHF aerial, flagstaff. I remember from physics these attract electrical charge
2. Dont pick up the chain with hands. If lightning strikes the boat your body will be a conductor. Not worth the risk - death potentially
3. stay away from the yacht masts as they attract charge and a stray fork could get you. Not miles away, but couple hundred metres
4. Hence I reckon it is better to stay in open water Quite close to the port/harbour and in sheltered water, but not actually among the yacht masts. These things are only 20minute affairs in the UK, so it's not a long wait
 
In the whiteout bit where the rain is so hard it hurts, you pull the throttle back to tickover and just keep that mental picture of where the other traffic is right at the front of your head. Your senses are then just overwhelmed. Then you dont even hear the thunder, you get this tremendous light flash (I swear not 10 feet from the boat, my crew agree!!) your body trembles, the air shakes and has a smell like a television on fire. Goosebumps on your arms.
Carry on to where you were going, only God will decide if you get there!!!!
Apres sail, well 'got away with that then!!'

Probably the wrong answer.....
 
I'd head towards the yachts, and the taller they are the better. Cloud to ground lightning will take the shortest route and hence being close to yachts with their tall masts make it less likely that I'd be hit in the Whaler, mind I'd not tie up to them! I'd probably drop the VHF aerial as well for additional peace of mind. I'd not go into open water as this would make me the only target above wave height :eek:
 
AdeOlly said:
I'd head towards the yachts, and the taller they are the better. Cloud to ground lightning will take the shortest route and hence being close to yachts with their tall masts make it less likely that I'd be hit in the Whaler, mind I'd not tie up to them! I'd probably drop the VHF aerial as well for additional peace of mind. I'd not go into open water as this would make me the only target above wave height :eek:
Click to expand...

Ah yes that makes sense. More sense than what I wrote, I mean :-)

It's not just a shortest route to ground thing though, it's shape of the conductor as well. If you have a yacht with a 20m high metal mast, and next to it boat with a 20m high blunt metal superstructure with nothing spikey, the lighting will go for the yacht mast because the electrical charge likes the pointy/spikey shape

Good WNS Tim!
 
AdeOlly said:
I'd head towards the yachts, and the taller they are the better. Cloud to ground lightning will take the shortest route and hence being close to yachts with their tall masts make it less likely that I'd be hit in the Whaler, mind I'd not tie up to them! I'd probably drop the VHF aerial as well for additional peace of mind. I'd not go into open water as this would make me the only target above wave height :eek:
Click to expand...

I'm not so sure. Most yachts will have the alloy mast grounded to the propeller shaft which supposedly provides a lightning protection zone.

I can't help thinking that lightning that has discharged thousands of feet to the earth isn't going to worry much about the conductivity of the last 30 ft.
 
planteater said:
I'm not so sure. Most yachts will have the alloy mast grounded to the propeller shaft which supposedly provides a lightning protection zone.

.
Click to expand...

A Scandinavian yacht suffered a strike this summer, arrived in Inverness with a hole in the bows, fortunately just above the waterline.
As I recall, the charge path was down the mast, and also down the forestay to anchor winch- chain- and out throught the hull to sea. Assorted other damage, as well.

edit- found a link-

http://www.inverness-courier.co.uk/...ning_strike_halts_round-the-world_cruise.html
 
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planteater said:
I can't help thinking that lightning that has discharged thousands of feet to the earth isn't going to worry much about the conductivity of the last 30 ft.
Click to expand...

Actually lightning travels up from the ground - its an optical illusion that it discharges from cloud to ground.

In this instance I would press on back to the berth as quickly as it was safe to drive, but:

Lower the VHF, flagstaff, etc as others have already said.
Turn off all non-essential electrical instruments at the device and at the electrics control panel; fish-finder, radio, even the plotter if you can do without it - make the boat as electrically inert as possible.
Get the crew to take off all metallic objects, watches, chains, even glasses if you can still see without them.
If you have a bit of rubber mat or rubber backed matting anywhere aboard bring it to the helm and stand on it. I keep one in the engine bay to kneel on while I work.
If you have rubber gloves in the galley give at least one to each member of the crew and get them to hold any stainless steel guardrails or hand holds with the rubber gloved hand.
Hopefully everyone has rubber soled deck shoes or wellies on.

Head for the berth staying well away from other boats - at least 30 feet, but then get into the berth fast and tie up and get everyone disembarked and off the pontoon into the bar as quickly as possible.
 
capnsensible said:
In the whiteout bit where the rain is so hard it hurts, you pull the throttle back to tickover and just keep that mental picture of where the other traffic is right at the front of your head. Your senses are then just overwhelmed. Then you dont even hear the thunder, you get this tremendous light flash (I swear not 10 feet from the boat, my crew agree!!) your body trembles, the air shakes and has a smell like a television on fire. Goosebumps on your arms.
Carry on to where you were going, only God will decide if you get there!!!!
Apres sail, well 'got away with that then!!'

Probably the wrong answer.....
Click to expand...


Captain...
Is this a piece out of your new novel :)......good story though.


North Up.....interesting link, thanks.
 
Here´s something no one has mentioned. Put all your portable electronic items (phones, hand held VHF etc) in the oven or fridge, which will act like a faraday cage and will protect them. This way if you are unlucky enough to be struck by lightning at least you have a chance of being able to call the CG.

Not sure how standing on a rubber mat is going to help on a plastic boat though.
 
I believe lightning only diverts 5 meters to hit a yacht so no benefit in staying clear of them.

This boat is so small/low I dont expect lightning will divert above 2 meters to hit it so just carry on.

Phone or vhf a shore contact to give an eta, put a hand held vhf, mobile phone and gps in a metal box (oven is a good place on a bigger boat as mentioned above) and thats about all you can do.

Not sure if radars should work in a white out but mine was useless in a hail stone white out.
 
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AndieMac,

I have, on 3 occasions, been in electrical storms of note. I can put hand on heart and tell you they are not nice. I have read all the advice, I have put electric gadgets in the oven and witnesed the 'optical illusion' at very close quarters.

When you are in those cirumstances, I can tell you that you realise the whole thing is as random as nature gets and anything you do is not going to affect things one slightest bit. Putting your boat amidst a thousand yachts will not garantee you dont get wacked. Its life!!

Does it stop me going to sea...nah!!!!

Cheers, Chris
 
capnsensible said:
AndieMac,

I have, on 3 occasions, been in electrical storms of note. I can put hand on heart and tell you they are not nice. I have read all the advice, I have put electric gadgets in the oven and witnesed the 'optical illusion' at very close quarters.

When you are in those cirumstances, I can tell you that you realise the whole thing is as random as nature gets and anything you do is not going to affect things one slightest bit. Putting your boat amidst a thousand yachts will not garantee you dont get wacked. Its life!!

Does it stop me going to sea...nah!!!!

Cheers, Chris
Click to expand...



Chris

We would rarely get a storm like these in our waters, I could only imagine the vunerability you would experience, especially hundreds of miles offshore, scary stuff indeed.
It is an interesting thread, I am hoping to learn more from folks who have experienced these events first hand.
 
strakeryrius said:
In this instance I would press on back to the berth as quickly as it was safe to drive
Click to expand...
Seconded.
I wouldn't even bother to lower the aerial etc., if that's going to delay the return somehow.
After all, the first element affecting the probability of being hit is the time of exposure at the storm.
 
Just FYI, on motor cruiser we usually put portable electronics in the microwave oven for protection while passing under a thunder storm (eg hh gps, hh vhf, mobile phone, etc). Microwave acts as a faraday cage and will protect electronics inside from electrical damage should there be a strick near the vessel or indeed on the vessel.
 
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Mine are also guesses, not based on any knowledge of the subject. I assume it's better not to be grounded if the lightening hits you personally, so on that basis stay under the canvas covers so you're not drenched through and in standing water in the cockpit? Is there any way wet covers would act as a Faraday cage? Probably not. Otherwise i'd just get to the marina ASAP
 
Its maybe 5 minutes to the marina. I d head for that. You are in a small plastic boat with an outboard low close to the water, so, out of ignorance, I d wouldnt expect it to be a lightening rod. You havent actually seen a lightening strike; its just sounding close.
 
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