I either take pictures on the way to the locker, during a break, or at the end of the day. As far as towels, we don't need them while we are on the rides & if I want to lay around I will just go to the locker. Still, you dry so fast anyways you don't really need a towel until you get in your car. I've always worried that someone (if you leave your bag sitting out) could easily take your car keys, find your car (just by pressing the lock or panic button) and take it while your still playing in the water.
Also be aware of your shoes. We always wear flipflops here at Water Country & just take them off before we ride, last week my oldest DD came back & someone had stolen hers. The concrete will kill your feet if you don't have shoes of some kind. Lucky for us we just wear our cheapo flipflops & this was the first time that happened in many years of going.