Michael Packard makes a living fishing off the coast of Cape Cod. He catches mostly tuna and mackerel. He drags for clams. And for three months every summer, he dives for lobsters. “It’s an extremely dangerous profession. I think about it a lot, but I try not to. I can’t dwell on it,” he told us. “You know, this is what I love. It’s a different world down there. It’s a whole different world.” Last summer, he had an astonishing encounter with a whale. Two weeks later he was back in the water.