If you are looking for a craft for your pack pool party or aquatics themed meeting, you could let the Scouts decorate their own pool totes. Then they can carry all of their squishy balls, goggles, dive sticks, and other pool accessories themselves.
Most craft stores carry plain canvas tote bags . Give them the plain bags and some fabric paint to decorate them. They can put their names on them and decorate them with fish or beach balls or whatever they like. Do this at the beginning of the get together so they are dry or at least mostly dry when it is time to leave. This would make a good gathering activity.