Marcus, all you can really do is go see what he does, and see if you like him. The only way you'll see who he really is is to take him home and get to know him.
A person can't really say he's going to like the water or what he'll like, because he's a mixed breed and isn't necessarily likely to carry any of the breed characteristics.
In general, mixed breeds are pretty freakin cool. Lots less troubles healthwise, too.
Border Collies aren't generally considered swimming dogs, Labs and and Retrievers are. That doesn't mean he won't like the water, cause lots of Border Collies do.
Border Collies will go straight through anything when they're working, mud, water, whatever. So in general, they aren't afraid of water, but they don't necessarily care to swim.
Not to belabor the Lab point, but I've never met a Lab who wouldn't play in the water all day.
