A professional diver doing rescue and recovery work for the Australian police, Brown has been attempting, for the last several years, to perfect a shark repellent which would protect both coastal swimmers and victims of disasters at sea from the attacks of these most vicious of predators -- ""the killers of the old and the weak."" His interest -- obsession is really the word -- in shark behavior began in 1960 after he witnessed the horrifying mauling of a young friend, Ken, a thirteen-year-old out for a casual swim. The boy died and Brown began his search for a repellent. The U.S. Navy and private researchers had tried a number of approaches -- chemicals, dyes, ""meshing"" off beaches and electronically created ""bubble barriers."" But, as Brown discovered, sharks in a feeding frenzy are oblivious to stench, poison and virtually everything else -- they're too busy, savaging and devouring anything they see including each other. Brown began experimenting with underwater sound waves and succeeded in attracting sharks via ""distress signals"" simulating a fish or a swimmer in trouble. But despite years of research in the atolls of the Great Barrier Reef and in French Polynesia, the attempt to create a ""sonic barrier"" has proved elusive. This report of Brown's research-in-progress details the ingenious equipment and frequently dangerous experiments which involved luring the sharks toward specially placed prey -- the tempting morsel often being Brown himself, He seems to know everything there is to know about the attack patterns, migrations and dietary habits of the White Shark, the Whaler, the Tiger and other man-eaters whom you'd never want to meet except in a book.