Sailors," says the Nouveau Petit Larousse French lexicon, "gave sharks the name 'requin' because their presence allowed no hope of salvation for a swimmer and was tantamount to a requiem."
Man has long been morbidly preoccupied with sharks. Pliny the Elder in the first century A.D. wrote of shark attacks on Mediterranean sponge divers, and during the 18th century the great Swedish naturalist Linnaeus announced that Jonah had been swallowed not by a whale but by a shark.
Evidence of fatal human experience with sharks has mounted over the years and has been documented even by such a fiercely objective authority as the Journal of the American Medical Association (July 22, 1944). Yet, scientists of established repute held that sharks were a harmless lot, and it was only a mass of grim evidence from World War II that once and for all made it tragically clear that sharks have no aversion to human flesh. Downed fliers and ship-sinking survivors reported too many grisly shark encounters to be ignored, and shark research has since been a serious occupation, with resultant interesting facts about shark life.
Sharks, for instance, although their stomachs have yielded everything from rubber boots to tin cans, prefer fresh food to carrion. They are, by and large, simply too slow to catch most fish, often must depend on cripples and flotsam for a meal. Furthermore, the majority of sharks have miserable eyesight, a highly developed sense of smell and do not have to roll on their side to bite. Their nervous system is wonderfully primitive, and they are virtually immune to pain.
The most recent fund of shark data is a booklet titled Airmen Against the Sea, published by the U.S. Air University and written by Dr. George A. Llano. It may be as practically significant for the beach buffs, yachtsman and deepwater anglers as for the hapless airmen.
In offshore shark waters, advises the report, "Swimmers should retain all clothing, particularly shoes. Evidence shows that among groups of men the partly unclad are attacked first, usually in the feet."
Aimless splashing tends to attract sharks; movement should be kept at a minimum.
If, though, a shark appears, there are rules which may keep the castaway intact:
1) Conserve strength. "Time is on the shark's side."