How dangerous is a thunderbolt of lightning while diving?

[lv2dive]

...Much the same happens when lighting strikes the water, the water and anything in it become charged but since the charge is equal all around no harm is done.
...

Perhaps that may be true in very large bodies of water but i think it is critical to be clear what one is talking about if they are going to say "no harm is done."

i know of at least one person who has ended up in the hospital from being on the surface near a lightning strike in a river/spring system. I know, second hand, of a few others who experienced symptoms at depth and needed to rely on support of buddy due to lightning strikes. Water is not always going to dissipate a strike.

 

[tracydr]

My dad is an electrician and he once told me I could cut an electric fence with his rubber coated wire cutters without getting shocked. The ground was soaking wet from snow melt.
My dog was stuck on the other side of a fence and couldn't/wouldn't come back through.
Well, he was wrong and that was a strong charger on that electric fence! Just about knocked me down!
Last time I believe an electrician when he tells me I won't get shocked. Uh huh!

 

[captain]

Perhaps that may be true in very large bodies of water but i think it is critical to be clear what one is talking about if they are going to say "no harm is done."

i know of at least one person who has ended up in the hospital from being on the surface near a lightning strike in a river/spring system. I know, second hand, of a few others who experienced symptoms at depth and needed to rely on support of buddy due to lightning strikes. Water is not always going to dissipate a strike.

If any part of you is at or above the surface near where the bolt hits, then you will get sapped. Best to be near the bottom but not touching it.

http://suite101.com/article/does-lightning-kill-fish-a144470

 

[knotical]

http://www.scubaboard.com/forums/basic-scuba-discussions/430054-diving-lightning-storm.html

Lightning and Diving

http://www.scubaboard.com/forums/basic-scuba-discussions/337783-lightning.html

http://www.scubaboard.com/forums/basic-scuba-discussions/205820-lightning-diving.html

 

[elan]

That was my point exactly. Being in the water is like sitting on a wire. The biggest voltage differential will be between two farthest points of the body. The better conductivity of the water the less differential will be between those points. Grounding the bird case is not applicable here as you are not touching the ground.

Actually the bird on the wire becomes charged (electrified) to the same voltage as the wire. It isn't harmed because no electricity is flowing through the bird to the ground. If you connected a wire from the bird to the/a ground the bird would be electrocuted. Much the same happens when lighting strikes the water, the water and anything in it become charged but since the charge is equal all around no harm is done.
An example of being at the same potential voltage of a power line.
[video=youtube;LIjC7DjoVe8]http://www.youtube.com/watch?feature=player_detailpage&v=LIjC7DjoVe8[/video]
This could be done without the suit but would feel very uncomfortable, sort of like an intense tingling over the body. Birds don't normally land on ultra high voltage power lines (50,000 volts and above) because of it, they sense it when they get close.

---------- Post added July 20th, 2013 at 02:07 PM ----------

the charge would not be equal all around, the charge is only equal all around if you apply the charge to a body made of dielectric, any body that has a finite resistance will have gradients of voltage levels. so there be a differencial between two points. One of the safety rules for the cases when a person happens to be by a power line with say a line fell on the ground is to make very small steps as the gradient between two legs will be the smallest.

I was unfortunate once to be about 100 ft from an electric pole that was stoke by lightening. We were all wet and we got quite an electric shock. It was harmful at the end inbut for a split second I felt like I was loosing a sense of reality.

Much the same happens when lighting strikes the water, the water and anything in it become charged but since the charge is equal all around no harm is done.

 

[Dsix36]

I don't agree with yr assessment.

I personally know three people who have been hit by lightening while diving and none that have been bitten by sharks.
-I have no fear of being bit by a shark...the reality is it is beyond unlikely: I'd have to be in the wrong place (eyeline of a great white or similar) at the wrong time (when it is so hungry/angry/scared it can't tell i don't look like food).
-I *am* concerned-and rightly so- about getting hit by lightening. As mentioned, I personally know 3 people who have been hit by lightening in the water, one with permanent cardiac repercussions. I also know of several other instances (one or two removed, not Kevin Bacon-related) with various degrees of severity.

Just making a point. I don't dive in thunderstorms even though I am usually "protected" underground in a cave.

Just because you are underground in a cave does not mean that you are protected. A budy of mine was cave diving when lignting struck the ground above him and obviously nearby. He would not be here if it were not for being rescued by his buddy. He was knocked completely sensless and silly but no long term effects or death at least.

 

[captain]

An example of a person's body becoming charged with electricity is when walking across a carpet on a cool dry day. You don't notice the charge accumulating in you until you touch a object at a lesser voltage potential than you and then you get a shock.

 

[ianr33]

Just because you are underground in a cave does not mean that you are protected. A budy of mine was cave diving when lignting struck the ground above him and obviously nearby. He would not be here if it were not for being rescued by his buddy. He was knocked completely sensless and silly but no long term effects or death at least.

I've heard of this happening twice. Once in Ginnie and the other in Hole in The Wall.
Pretty scary to think you can get zapped by lightning a couple of hours after entering a cave on a perfect day!

 

[lv2dive]

Just because you are underground in a cave does not mean that you are protected. A budy of mine was cave diving when lignting struck the ground above him and obviously nearby. He would not be here if it were not for being rescued by his buddy. He was knocked completely sensless and silly but no long term effects or death at least.

Understood - I thought I had that covered in my first post* and I intended sarcasm with the word "protected" that is why I put it in quotes. Obviously a bit of a fail on my part .


*I also know of several other instances (one or two removed, not Kevin Bacon-related) with various degrees of severity.