Awesome pics! I used to have a yellow lab that would swim long distance like that. We had to get him a neoprene vest because he would exhaust himself swimming after sticks/tennis balls in the river and was in danger of drowning when coming back upstream. Couldn't get him out of the water though.
"Dopey", my Carolina dog. It was a rescue dog - I never even heard of "Carolina Dogs" before it was given to me. Weirdest dog I've ever known - we get along great. Experts say that Carolina dogs evolved this protective coloration during the Mid-Century Modern epoch, enabling them to evade their greatest foe, exertion.