Murphy got his swim today. In fact, he got a real work-out, because instead of me throwing his toy like normal, I use the curved plastic tennis-ball-whipper and that thing zings the ball half way across the river. So he really gets to swim, going half way across the river to get the ball, then bringing it all the way back.
And I have to be careful to only throw the ball half way or a bit less. Any further and Murphy could decide that the far shore is closer and more convenient and it's be a ten-minute drive for me to go down to the closest bridge and back-track to any exit point over there.
And yes, he's that smart. Gotta watch this dog every minute.