Allen Du Mont, founder and chairman of Allen B. Du Mont Laboratories, Inc. and the first man to put television into America's living room, is a skipper who knows no greater delight than to guide his powerboat by dead reckoning through a heavy fog in Long Island Sound. Du Mont is a devotee of predicted-log racing, a nautical exercise requiring each skipper to calculate and record the details of the race he expects to run before he even starts. He must predict the time he will pass markers moored between start and finish and must complete the course without a chronometer. This year, as three times previously, Du Mont piloted Hurricane III, his 54-foot Annapolis-built cruiser, to national honors for power-cruiser predicted-log tests with near-perfect accuracy. Because contesting navigators must estimate, among other variables, currents, tides, wind and the boat's increasing buoyancy as fuel weight decreases, Du Mont's achievement, compiled over a long summer's competition, is remarkable. A 58-year-old selfmade electronics pioneer, Du Mont combines a fiercely inquisitive spirit with optimum caution. Predicted-log racing is clearly his sport. Says Du Mont: "I find it relaxing to concentrate."