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Lightning- how to avoid

Posted: Thu Oct 18, 2018 2:27 pm
by theodosius
Is there anything that can be done to minimise the risk of a lightning strike while out on the boat? Rods in gunwhales I assume, any other ideas? Stand on foam?

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 2:56 pm
by jeffish
I reckon just sit down and put your head between your knees and get ready to kiss your arse goodbye . :smoking:

Seen a few come close and have had a sounder fried when a bolt hit the water 20mt off the stern . so I now turn all electrics off get the rods down and try to insulate myself as best as I can .

Be interested to hear any ideas people have , but I have spoken with many sparkies and rescue teams about strikes and most say the same as my first comment . :kiss:

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 3:42 pm
by NinjaFish
Make like this if you can :captain:

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 3:52 pm
by Matt Flynn
Yep, escape early. I would crawl under my high casting deck, hoping it would act as a Faradays Cage. But it probably would have been a fast roaster.

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 4:05 pm
by NinjaFish
Seriously though :D

We got caught up in one of the Territory's best out at Shady last year about 4 in the morning and all I could think was 'the things I hadn't done yet in life!' I just bolted to a wider bend and dropped anchor far enough off the banks to allow for the swing, dropped all rods on the carpet floor, -not in the sides and turned off all the electrics and isolated the batteries then dropped the marine radio aerials and stood under the bimini without touching any aluminium parts.

To say it was electric would be an understatement and still to this day that storm was better than any showride I'd ever been on and we got hit from all sides with the wind and rain and a headache from the light show that we could feel through the hull but hard to explain. I'm still here and no effect to the boat which considering we were just a big chunk of ali sitting in the middle of it all still has me scratching my head.

Have had numerous HF Codan radios destroyed by lightning and Engel fridges through surge but only on land and while hooked to power.

Like Jeff said :D hang on and hope your deckie doesn't smell too bad as he will get very close to you when you get caught out. :D

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 6:45 pm
by theodosius
Yeah hard to imagine a better target than an ally hull, especially when there's just scrub and water around. Had a patient once who was badly injured and it's been in the back of my mind every buildup/wet trip!

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 7:13 pm
by NinjaFish
Appropriate timing or just because it's that time of the year?

https://www.abc.net.au/news/2018-10-18/ ... t/10365414

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 7:22 pm
by Captain6979
YODO.....You Only Die Once...ha ha! Yes, I can't say id like to be in the Punt, as a big 'Leccy storm hits..be like sitting in a john west can in the Toaster!

Re: Lightning- how to avoid

Posted: Thu Oct 18, 2018 8:00 pm
by theodosius
NinjaFish wrote:Appropriate timing or just because it's that time of the year?

https://www.abc.net.au/news/2018-10-18/ ... t/10365414
Hmm... within a metal roof vehicle- does a canopy count?

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 1:21 am
by mickkk
I was under the impression that you put the Bimini up to create a cadge and lie down on a mat if you have one, otherwise straight on the alloy floor. The more contact with the floor the shorter the distance the current has to pass through you. Would happily be corrected if I’m wrong, I don’t really know if I was told this, or just thought it up whilst on a sketchy trip

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 6:27 am
by ronje
Agree with Jefffish.

Kiss something goodbye (maybe not the deckie?).

My view is to make yourself the lowest point around. Bit hard of you're in a boat on the water because you then ARE the highest point around.

Don't put up a bimini as you're making yourself even higher PLUS you're hanging onto the highest lightning conductor around with the bimini frame made of metal. The job of a lightning conductor to attract the strike so I wouldn't be hanging on to IT. You'll attract a lightning strike alright.

Ditto with rods (lay them flat in bottom of boat).

Don't stand up as you're inviting a strike. Keep all body (including yr head) lower than the boat sides.

A strike will come once the static electricity builds up on the highest point around to create an easy path to the oppositely charged cloud above. Just make sure that you're NOT the highest point around.

that we could feel through the hull but hard to explain.[/i]. That'll be from the static electricity increasing and decreasing in your surrounding area with strike activity.

I haven't experienced that but have had hairs on arms and head (when I had hair) prickle up once. That's a warning sign (if you're lucky) that you need to take notice of. That was a bit fierce to frightning.

Mains 240v will kill and there's only tiny amounts of current involved.

Thousands of amps in a lightning strike. Enough to evaporate thick copper busbars leaving only blobs of solidified molten copper around the area.

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 6:31 am
by Matt Flynn
Remove all metal objects from body, they can burn into you. Bad time to have metal fillings, but if they are affected it probably won't matter.

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 12:36 pm
by NinjaFish
I have read somewhere about melted fillings from people that got struck.

You know it's close when you hear the raw power of the whistle and a wild crackling as it's coming down then a real loud snap.

The static you speak of Ron had a sort if humming or buzzing sound and I kept getting asked if I had turned everything off properly and "are you sure, I can hear something".

An experience I've had a few times but I can assure you it scares the cr*p out of me and I've outrun more than a few to get away. Bynoe is a good place to run from one end to the other but that's mostly because you can see it coming. 8)

Anchored off Talc head late one night with a beer and a few rods on a mates boat, a nasty storm blew up and we pulled anchor to head back into Woods Inlet. Before we got around the point and into the channel the rain became torrential and skipper engaged the autopilot to be sure. Still peering through the windows a bolt of lightning hit the bow rail or anchor and blinded the both of us, the result, it blew the radar and threw the circuit breaker on the generator and again, another bl**dy headache.

It took nearly two hours before my blurred vision stopped completely and can only be described as a welding flash x 1000 and without the burnt red eyes.

Lightning - Best enjoyed from a great distance. :moon:

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 2:09 pm
by ronje
I've only had that sort of experience once when I arrived home late half blotto after promising to take missus out for her birthday. No sense of humour at all.


The last thing I'd be doing is dropping the anchor to the bottom thus making an even better earth for the "floating lightning rod" (the boat).


https://www.youtube.com/watch?v=6MUYsIjTKvk

Have a look at this link. How a lightning strike happens.

As the static buildup in the cloud increases, a "leader" comes down looking for the nearest object to connect itself to.

That leader ionises the air column as it comes down decreasing the electrical resistance to earth. That ionisation is actually ozone being ionised and gives off a smell. The increased voltages also cause your hair to be attracted upward as your tallest point (your head) is closest to the opposite charge in the cloud above you.

Once one of the leaders (there are usually several) hits a suitable "earth" (could be a tree, your head, mast or rod), the ionised path is established and the discharge is then made by thousands of amps of current.

Not a nice place to be near. The crack is the sudden discharge exceeding the speed of sound. A sonic boom right beside you.

The flash is "eye catching" to say the least but at least there's very little UV light generated or a dose of UV of that magnitude would kill every living thing anywhere near it.

Its the UV given off in the welding process that causes welding blindness.

Colours are determined against a temperature standard. That standard is determined by the temp measured in degrees Kelvin which is absolute zero and is in reality -73 degrees Centigrade.

You've probably heard of LED lightbars with colour of 6000 or 5000K. That's what the K is. Kelvin. 6000K is white light from a 6000 Kelvin degree temperature.

4000K is yellowish like sunlight or a normal incandescent globe.

Ultra-violet is well above 12000K and beyond the range of visibility of our eyes. Especially UV b or UV c.

And THAT UV is what the welding process generates and why you get temporary eye damage.


Hows them apples?

Re: Lightning- how to avoid

Posted: Fri Oct 19, 2018 5:17 pm
by NinjaFish
I like apples and know at least four Kelvins but they're not that bright.

You have enlightened ( :roll: ) now a bit more to me about the sideway travelling lightning that never seems to go anywhere but across the sky.

Excellent link and the follow ups make me think!

:cheers: