Oh my, why didn't I think of that? My pool is outdoors and I was literally moving small rocks from one pile to another
I was trying to think of something like a baseball pitch counter, but it would rust.
I have a row counter sitting right here in my knitting supplies, but now I will have to wait until next year to use it, we just closed our pool this week. Thanks for the idea, I like to let my mind wander while I swim and I lose track of my laps constantly! Hmmm, maybe this could help me keep track of intervals on the treadmill too. . .