Do sharks always hang around as a group?

Sharks can approach VERY much to the coastline, in VERY shallow waters, but there are no shark species that will deliberately swim to the sand in a beach to pursue a prey, like the killer whale (Orcinus orca) when attacking seals resting in the sand near the water.

Just to give you an example, the very large and dangerous tiger shark (Galeocerdo cuvier) have been observed in depths as shallow as 3 metres, normally thought to be too shallow for a species of its size.

Bull sharks (Carcharhinus leucas) can be found in even shallower waters (specially in freshwater, far away from the mouths rivers).

Last year, an adult swimmer named Lungisani Msungubana, aged 25, was killed in the second beach in Port St. Johns, South Africa, by a bull shark in waist-deep water. Only his amputated body torso was recovered, after a three-day search for his corpse.