When someone suggested to Kathie Hewko in 1976 that she should try swimming across San Francisco Bay, she wasn't buying it. "I said, 'Are you crazy? There are sharks out there and the water is freezing!' " she recalled. Apparently, she got over it. On April 17 she completed her 80th swim across the bay and under the Golden Gate Bridge, reaching the tip of Marin County in about 30 minutes. She hasn't encountered any sharks in the bay, she said. And as for the water temperature -- well, it is what it is. Fifty-one degrees Fahrenheit -- which was the temperature when she swam on April 17 -- is no big deal, she insists. She's seen colder. "The first time I swam to Alcatraz Island, it was 45 (degrees), and that's about as cold as I've done," said Hewko, a Petalu...