It's inherently contagious
He also instinctively slips one foot under a hiking strap. Smart lad.
I think he has been watching Tom Slingsby too much. Hiking with the feet that far apart can't be efficient.
You have it all wrong - he is in tacking mode - one foot under and the other on the way over with hand on tiller - but you should have a grandfatherly moment with and tell him it is better to be looking forward as he tacks.
and he's wisely chosen a Mac. well done, Owen.
"Dat's me bwogging!"