It seems obvious that kayaking in electrical storms is probably not a very clever thing to do, but would love to hear from somebody who actually knows.

The reason I bring this up is because at our local playspot (Sierre) we often paddle in the evenings when the water is at its highest, but that is also the time when electrical storms are most frequent in the Alps. Very often we are getting happily trashed when along comes an electrical storm. Because there is a huge metal bridge about 50 m above the wave, we tend to stay on the water thinking that the bridge would be a better target (earth) rather than a humble kayaker.

Is there a kayaking physicist out there who can confirm that highly dodgy hypothesis? Anybody know of a good text or link on this subject?

I guess there are times (on wilderness or sea kayaking trips) when you dont get much choice about getting off the water if a storm comes along. What is the best thing to do if you get caught out in the open?

In mountaineering there are very clear procedures about what to do in case of getting caught out in electrical storms, is their a similar guideline for kayaking?

This might help......
www.boatsafe.com/nauticalknowhow/lightning.htm
I'd explain it myself but its too complex for my feeble brain(hard to explain).

A mate of mine, Dave Rice will probably know. He's a kayaker and an electrical engineer. I'll get him to post something.

The one day at the Vaal I was paddling with some mates when a big storm came. They all buggered off but I stayed. It was a great play session but probably not the wisest of choices.

In our summer the wind is not great and I often windsurf in the winds before/during/after a thunderstorm. It's great but short lived and dangerous. Lightning has hit the ground within 30 meters from me twice just as I got off. I try not to sail in these storms anymore but it's a good rush. Like they say, the more you throw heads, the more likely it is to land evens.

Do you have any photos or perhaps GPS co-ords of the spot?

See: playak.com/article.php?sid=1224

The one day at the Vaal I was paddling with some mates when a big storm came. They all buggered off but I stayed. It was a great play session but probably not the wisest of choices.

You are one lucky boy, Ades. Steve Fisher was struck by lightning some years back while playing at Gatsien on the Vaal.

scottyr wrote:

You are one lucky boy, Ades. Steve Fisher was struck by lightning some years back while playing at Gatsien on the Vaal.

Ooops! hehehe, it was quite a solid storm but the bottom wave was working and it was too tempting. Given the open terrain and Steve's experience I think I'll go up to Stonehenge for a meal next time.

Apologies for the late response. Please don't consider this a proffesional opinion, rather a semi-educated one I presume a lot of this would be consistent with lightning safety procedures in the mountains as well?

The short answer is: you're only safe from a lightning strike if you're in an electrically shielded environment (i.e. enclosed in a conductive cage, which ideally should be earthed too). This is why you are relatively safe in a car (not because the tires are rubber). When considering the risk of getting struck by lightning in a particular area, the ground flash density (average number of flashes, or strikes, that hit the ground per sq. km per year) for that particular area needs to be considered too. Protection measures are normally implemented at sites as a function of both ground flash density and also the type of site (eg. an explosives factory would require much higher protection than an office building).

In general, the safety zone for lightning is a radius of 10km (note that if you're using the Flash-to-bang method of calculating the distance that this relates to almost 30 seconds). Higher elevations and tall free-standing objects (like large trees) should also be avoided (so being on the water a few metres from the nearest tree branch is safer than being on the bank under a tall tree). This is because if the tree is struck by lightning, the flash will travel down the tree and could possibly see a human body as a better path to earth (wood is not a very good conductor) as it gets near the ground and arc to it. This is known as a side flash, and can also occur in open, unprotected (i.e. not properly earthed) shelters (eg. picnic shelter). When lighting strikes the ground, it also causes a Another thing trees is that they tend to explode when hit by lightning - the lightning current causes the the small channels of water in the wood to flash-boil. If you're stuck in open ground (i.e your head is now a relatively tall, free standing object) the only thing you can do is to try and find the lowest point, and crouch down as flat as possible, keeping your feet together.

So, back to the river. Obviously You're also much safer being on a river (as opposed to on top of a mountain) because you're already at the lowest part of a valley (dependant on the steepness as well I think). I guess you could follow the logic to say that you should find the lowest point nearby, like just in front of the foam file, and stay there until the storm passes Seriously though, if it's a park and play spot, the best thing to do is climb into the car (as long as it has a metal roof and the windows are closed) and either wait it out or go home. Somewhere like Gatsien, the best thing would also be to leave before the storm gets there. Although when I did get stuck there a while back, we ended up waiting out the storm in a bit of a depression on the left bank under a raft, well away from the trees. Does anyone know where Steve was when he was struck?

The bridge at Sierre is probably a better target for a direct strike (depending on how high above the water it is) but it could potentially flash to the water depending on how the bridge is earthed at either end, soil resistivity, etc. It's also possible to get injured during a lighting stike from an upward leader, which the bridge would not neccesarily protect you from. A lighting strike happens when a downward leader (from the clouds) meets an upward leader from the ground (the main current of the strike actually then returns back up this channel to the clouds). Many upward leaders are formed from all nearby prominent object though (as the downward leader gets closer to the ground), and these can have currents large enough to cause injury should you have one go through your body. So you don't actually have to get struck by lightning to be injured by it. (This happened at a local soccer game a few years back).


Ok, sorry, this turned into a bit of a collection of lightning trivia, and a bit longer than I intended Hopefully it's vaguely understandable though, bit of a complex subject to explain in a forum post though...

Nice one Dave. Shot for that.. Quite a few variables there. Interesting

Cool - thanks for that explanation Dave - it is really useful info and has convinced me to sit-out the next electrical storm in the car. In any case they usually blow over quite quickly. I think that this is exactly the sort of thing that forums should be about - sharing knowledge to improve safety awareness. Thanks - Ian