This weekend marks the unofficial start of summer, but it's also John F. Kennedy's birthday. And who better to model your easy-going summer style after than JFK? Sure, he was a sharp dresser when it came to suits, but the president was more known for his comfortable nautical style, which he developed while sailing around Cape Cod. Broken-in chinos, salt-washed polos and cotton cardigans topped with tortoiseshell shades and grounded with pragmatic boat shoes or canvas sneakers. They're the kind of effortless, masculine duds that looked just as timeless in the 1960s as they do right now.