I wouldn't suggest a Whaler if you also want to be doing water training with it ... that's a big ol' boat for a dog to practice towing.
Honestly, I'd drop the idea of trying to combine two into one unless your idea of fishing is paddling out onto a small lake. You'll want to mount a platform on a boat for water training and while I suppose you could take it off for fishing, I doubt that would be much fun. And there's no way in the world I'd spend that much on a boat for water training.
Plus, a fishing boat you will probably want a motor and it's not say you can't take that off for water training, but it's just one more thing to have to switch over. If I were you I'd scour the used boat Web sites (and there are tons, in addition to eBay motors) for one of each. Maybe you can find two boats that can fit on the same trailer or something and save in that dept. A boat for water training doesn't have to be fancy since really you're never more than 50 feet from shore in it.
Fortunately I'm lucky enough to occasionally be able to train with people in our regional club who have boats, but we do most of our training at home. You know what kind of boat I used to practice towing last year? A 7-foot rubber inflatable type loaded with a few spare cobblestones. Granted, that only works for the junior exercises, but it's a start.
[ 03-20-2006, 09:45 PM: Message edited by: Sailorgirl ]