There is apt symbolism in the sight of Alcatraz—"The Rock"—as backdrop for a swamped sailboat: they are both, in a sense, monuments to the folly of man. A sailboat isn't a trolley car, but it shouldn't tip over in moderate weather unless—as both sailors and convicts frequently mutter about their misfortunes—somebody goofed, or there were circumstances beyond control. Last week on San Francisco Bay, Keith Buck's 30-foot sloop capsized when a gust of wind hit her sails during a jibe. At left: the crew of three men and a woman bob sheepishly about, unhurt except for their pride, awaiting the Coast Guard launch. Below: Buck secures the tow before the long, chastening ride to the mooring, where the yacht and its occupants dried themselves out.