Lightening and water

[Mike P]

I was watching the lightening from the safety of home and due to my inattentivness at school, I wondered what if the lightening hits the water near a diver. Deep fried or an unpleasant experience?

[Smudge]

had the experience of being in the water in malta during a lighting storm. Not only in the water, but this was a night dive!
Fantastic light show from under the water - shore cover wern't happy. They told us that the storm had hit several times near by!

Physics of electrical current says when it's hit the water it's earthed out - nothing to worry about as long as you keep your head down..

smudge
www.proscuba.co.uk

[Paul Oliver]

Me and Blan dived the Warilda during a Thunderstorm, i thought there were some very powerful strobes down there at 48m until the penny dropped.

We were fine underwater, however i don't think Ivan and his dog were too chuffed on the boat (Michael Mary).

[Ferg3333]

I had a similar experience in Turkey . At 33m the whole water column lit up it was awesome.

[stewbie]

Stoney last week

[Dave Sydenham]

It's the big bit of metal strapped to your back which would worry me!!

[Stesh]

Originally Posted by Dave Sydenham

It's the big bit of metal strapped to your back which would worry me!!

Naaa lighting would hit your snorkle first and at worst melt your fillings if you were using it at the time

[Dave Sydenham]

I guess you'd probably be OK as long as you had rubber flippers on!

[Richard Mason]

Originally Posted by Mr Grumpy

I was watching the lightening from the safety of home and due to my inattentivness at school, I wondered what if the lightening hits the water near a diver. Deep fried or an unpleasant experience?

Personally, I'm guessing that were it to strike near you, most of the electrical discharge would go around you rather than through you, based on the fact that I reckon saltwater would be a way better conductor (due to all those Sodium, magnesium, calcium and chloride ions) than human body fluids which are much more dilute solutions. Add to that your rubber suit (especially drysuit).

Of course, if only 1% goes through rather than around you and the water around you takes 100 amps - ouch, that would probably nbe fatal. So it depends how close you are to the point where the bolt "hits" the water and maybe, whether you are in a wettie, a drysuit or shorts & t-shirt.

Also, you orientation when it hits - if you had your head pointing towards the strike and your feet away from it, maybe the differing field strength between your extremities would be enough to encourage the charge to jolt through you.

I suspect that in that last para, I may be talking bollacks though

Richard M.

[Janos]

I'm a freelance scientist, and what you've experienced is technically what's known as a "judder".

Ok. I'm not. But I did do a bit of Physics at school. Basically as soon as the lightening hits the surface of the sea it's gone. If you were in a cave on (or rather under) dry land you'd be fine, and sea water is far more conductive than dry land.

Also you have to ask: where is the lightening "going"? The strike is because of a difference in charge between the sky and the ground / sea. Once the spark has connected the two that's it - lightening finished. In fact I'd be willing to be that if you were at 2m in Wraysbury and the lightening struck the surface above your head you'd be ok.

As aside, I was once in a plane that was struck by lightening. That was scary.

Janos