My daughter has a year-old sprocker called Moose who is lovely, clever and well trained, but impossible to tire out -- if you're happy to play fetch and throw a stick or a ball for several hours, she's happy. When they spent a week on a boat with us she had her very own "special" stick which started off several feet long and ended up just long enough to throw. Oh yes, rather keen on water too, only went in the cut a few times...
Combine that with the collie herding instinct and flightiness and you're in for a whole *heap* of fun -- or trouble, as some may call it, he may end up mad as a box of frogs... 😉