On a recent Friday morning, a line of bathing-suit clad students stood beside a campus swimming pool, waiting to jump in. They had come to persuade the University of North Carolina at Chapel Hill they were worthy of a college degree — which they were not, in UNC's eyes, until they could swim 50 yards and tread water for five minutes.For many, it was an annoying inconvenience, for others a moment of pride in conquering their fear of water. But the scene also was a small slice of collegiate history. This was the last swim test day at one of...