Well, since I started this post, and the new puppy turned two last month, I figured I'd chime back in. The last day on the water this season, I taught my dog how to dive underwater off the swimstep -- to chase after a water bottle with 1-2 bubbles of air (just enough to float back to the surface). Once he actually figured out what I was trying to get him to do, he was able to dive about 4 feet underwater and come up with the bottle in his teeth. It was definitely a crowd-pleaser. Until he started peeing and puking all over my carpets. If I remember correctly, he pee'd three times, and puked twice?? Anyway, he's a great dog and he'll still be out with me next summer. But no more diving.