Edward was entirely unconventional. His long-term lover was a man, Piers Gaveston. His interests were un-kingly, ranging from rowing, estate management (including digging his own ditches), music and swimming.
He liked mixing it with common people, and according to a written source "spent a month swimming and rowing in the
Swimming was considered far less than appropriate for a King, and was not a common activity.
I wonder how he learned, and what motivated him?
I first read about Edward II's swimming proclivities in this book, Haunts of the Black Masseur: the swimmer as hero, by Charles Sprawson (1992). I'll do a review and separate blog entry on this book at some time