Is it safe to swim in a lake during a thunder storm with lightning?

**......** · 06-03-2010, 10:38 AM

Tonight my friend and I decided to swim in a lake during a thunder storm with lightning. There were trees around, so I figured if lightning did strike, it would strike one of the trees. Was it safe to swim in that lake? It's really more of a pond, probably the size of a basketball court, with trees around it.

**Michel Verheughe** · 06-03-2010, 10:39 AM

Having sailed for nearly half a century, I have read a lot about safety at sea. Here is what I learned:

If the lightning is to strike the sea within a radius roughly equal to the height of your mast, it will hit it; else, it won't. This would then also be valid for a tree. I suppose the pond was larger than the height of the surrounding trees so, there was still a chance to see the lightning striking the water.

But would that be fatal for a swimmer?

Electricity can kill in two different ways:
1) A heart fibrillation induced by an alternative current.
2) The burns from the heat of a continuous current.

In my humble opinion, if the lightning doesn't strike you directly as you swim, you have a good chance to survive but ... expect a shock and perhaps loosing hearing for a while.

Also note that when lightning strikes, it first makes many branches from various places on the ground and in the clouds. It is only when one branch is so hot that air turns into plasma, that the main bolt is formed. It happens in a fraction of a second but if you are hit by one of the first "probing" branches, your chances of survival are high.