Another tip...Since it was a non-
Disney cruise, I would hang the fish extender inside the cabin so nothing was taken out of it after being filled. To fill, my DH would take the boys to wherever we were headed and I would either meet them in the elevator lobby claiming I had to use the bathroom quick or I would meet them at our destination on the ship! So when we returned to the room...Ta da, all filled! DS15 knew I was filling them but he didn't care as he loved what he was getting!