Swimming indoors during a storm

At my gym they get you out of the pool for 30 minutes if there is thunder or lightning.

I didn't belief it when I read your post but I found this:

http://www.lightningsafety.com/nlsi_pls/indoor_pools.html

So I guess there is something to it.

Same here - 30 minutes after last lightening strike.

This is one of my pet peeves about the pool on Ft. Hood.  I understand them shutting down when storms roll through but I swear the thing is closed every time there is lighting strike somewhere in Texas.  Seems like it closes half the summer!!

This is so stupid.  I looked (and found that others have looked as well) and there isn't evidence of a SINGLE death ever from swimming in an indoor pool and being harmed by lightening.  "We could find no reports of deaths or injuries in indoor pools related to lightning causes," says Richard Kithil of the National Lightning Safety Institute and Kevin Johnston, a senior consultant.  (from http://www.bigeye.com/indoorswimmingpools.htm)

Of course, I suppose you should close the indoor swimming pool if a tiger escapes from the zoo as well.  Tigers have recently been found to be able to swim and sometimes actually hunt from the water, and a Tiger COULD possibly get through a door as someone is leaving.  

Liability, liability, and liability.  Nobody wants to get sued over the outside chance that it does happen. So they err on the side of caution.  I could go on and on about "these days" and society as a whole, but everyone knows already.