|Lothrop, Lee & Sattler, Helen. Sharks: the Super Fish. New York: Shepard, 1996.||"But when they are chasing food or escaping enemies, some can swim very fast, up to forty miles per hour."||18 m/s|
|Encyclopedia of Aquatic Life. New York: Facts on File, 1992.||"The Mako shark is probably the fastest fish in the world. It has been recorded to swim at speeds over 95 kilometers per hour. And is known to out swim and eaten swordfish."||26 m/s|
|Steel, Rodney. Sharks of The World. New York: Facts on File, 1985.||"A leap would require an initial take off speed of 35 kilometers per hour (22 mph). The maximum speed these fish can achieve is probably around 56 kilometers per hour (35 mph)."||9.7–16 m/s|
|McGoven, Tom. Album of Sharks. New York: Rand McNally, 1977.||"The fastest shark is the Mako which can reach 50 km/hr."||14 m/s|
|Mako Shark. Enchanted Learning Software.||"Estimates of their speed varies; some say that they can swim at over 60
miles per hour (97 kph), while more conservative estimate rate are of about 22 mph (35 kph)."
There are 354 different species of shark. Sharks are strong animals with very powerful jaws, some of which are capable of killing a human. Sharks vary greatly in size and habitat. Whale sharks are the largest. They grow up to 40 feet and weigh up to 15 tons. On the other hand, the smallest shark is 6 inches long and weighs only one ounce. The great difference in length, fin shape and weight results in a great difference in velocity. No firm figures in speed have ever been determined due to this situation. Usually a shark's speed is measured while it swims along with a boat. This procedure contains sources of error. It can not be determined if they become tired easily, lose interest or simply want to escape.
Smaller, lighter sharks such as the mako and tiger shark swim at high velocities. Heavier sharks such as the whale shark swim at much lower speeds. The normal cruising rate of a typical shark is 2 miles per hour during the day. At night, when the shark is more active or on the hunt its speed is greater, however, sharks can only swim short distances at high speeds. The speeds I collected ranged from about 10 to nearly 30 meters per second.
Jennifer Puglia -- 1999