There are few more predictable reactions than to go to a crowded beach and say the word "shark" loudly enough. Nothing you say before will matter, all people will hear is "shark" and immediately think that anyone in the water is going to find themselves on the receiving end of a violent and fatal attack by an unthinking man-eater. The panic is mostly unwarranted. Out of all the over 470 species of shark only a handful attack humans with any kind of regularity, and here are five of the many hundreds that don't.
Though large enough to be potentially dangerous, the Caribbean reef shark is generally either shy or indifferent to people in the water (though they can also be somewhat curious). Aptly named by being found solely in the Caribbean, these sharks generally grow up to 10 feet (3 meters) and are one of the few species of shark that can rest motionless on the sea bottom. Caribbean reef sharks are also frequently the main species seen at shark feeding dives in the region, and though the presence of food can make them more aggressive even then there's little harm.
One of the better known species of shark, nurse sharks are usually the first species that comes to mind when people think of non-aggressive sharks. Sluggish and nocturnal by nature, nurse sharks are best known for resting motionless in caves and crevices with no attention whatsoever paid to people. They can reach a maximum length of 14 feet (4.3 meters) and let me tell you, it's always a surprise to swim down to a coral head and find one of these resting underneath it.
Measuring in at 4-5 feet long (1.2-1.5 meters) the tiny leopard shark takes the number 3 slot. Extremely wary, the leopard shark's first instinct to humans in the water is to flee (there's a sentence I'm sure you never thought to see). Despite their small size leopard sharks are very hardy and adapt to captivity well, which makes them highly prized by the aquarium trade.
The largest known extant fish species in the ocean, the whale shark would win any non-aggression contest held. For all it's formidable size, growing to lengths of over 40 feet (12.5 meters), the whale shark is a filter feeder like many species of large whales (hence the name). Like the others on this list the shark is generally indifferent to divers, though younger sharks can be more curious and playful than older individuals according to anecdotes.
The hands down strangest shark on this list, the angel shark, looks a little like over sized flounders. As one would imagine angel sharks are ambush predators that bury themselves in the sand or mud to wait for prey to come swimming by. It will either remain hidden or swim away if humans approach, but if provoked or disturbed it can inflict a severe bite to the offending individual.