[upthesaukee]

Not so much the training not to chase waterfowl, but to come when called.

If your dog will not come when it is called, then I would have concerns. I had black labs that I used for duck hunting, and they did respond to voice and hand signals. I had no fear of them swimming off, because they would stop on command, and then return if they were so instructed.

If your dog would continue to swim after the waterfowl, and there are enough to be concerned, you may very well need to keep your dog tethered. They can tend to swim out farther than they can return. I share your concern.