To many Chicagoans, the beaches are fine for toe dipping but no place to go for a real swim on a steamy summer afternoon. That's because the lifeguards tend to want to do their jobs, which, in the view of some authority somewhere, means no one is allowed in water much deeper than the average adult's sagging waistline. Officially, it's not any better along the rest of the lakefront—as sign after sign warns, swimming off the seawalls and breakers is a fineable offense. Unofficially—and thankfully—Chicago has a generations-old tradition of decriminalizing swimming at certain spots known mostly to neighborhood regulars. While I'm all for diving in anywhere I can, I've found the most impassioned and daring swimmers and splashers just south of the Foster Avenue pier. I was there one lazy Sunday last summer when the leaping and diving was briefly interrupted by the sight of a runaway inflatable raft drifting a half mile offshore. A guy lounging on the seawall set his beer down and declared that he was swimming out to get it. He was 50 yards into his journey when a motorboat zoomed over and scooped the raft up. He swam back to his beer, and the cannonballing resumed.