We just discovered a really nice (free!) lake in a town near us where our good buds Mark and Jamie live. As usual, Will did not want any help from us while he flung himself repeatedly into the lake...so needless to say, it was a bit high maintenance. However, we got in 2 fun hours before thunderstorms chased us away.
Mark and Jamie brought their big tubes from the boat, which Finn and Will had a blast playing with.