“That’s where the crib dock used to be,” he said, pointing at the single, well-worn cedar post that reached upwards from a rock cluster on the shore. “Your great-grandfather made it with the help of his neighbours.”

His chair faced the large living-room picture window that overlooked the fresh waters of the rocky shoreline of Georgian Bay, two hours north of Toronto. On the arm of his chair sat his eight-year-old granddaughter, Emma, whose arm was draped across his sho...