We've had good boat dogs but I wanted a very small size(under 20 pounds) after our Springer Spaniel that sailed with us for years. By their life jacket strap, it's like picking up a six pack.

They're robust walkers, you'll wear out long before they do. Both of ours swim but one is near Olympic quality which I never expected in a Jack Russell Terrier. I often lower them out of the dinghy long before we get to shore. They're hard to keep up with.

I know some terriers that don't bark too much. Two terriers(which we have) makes them noisier. They're very bright and have a very strong personality which doesn't make them the right dog for all people. The perfect boat dog would be 15 pounds, have a personality like Nat's Doodle, be a real walker(many calmer little dogs aren't good walkers), and only bark when somebody turns on a generator.