The Beach People are the various people on LA Beach during the first act of The Beach. They range from an overweight white women to a chilled out black hipster to a narcissistic Lifeguard
Dan makes several attempts to snuff them out, ranging from simply covering them with sand to unleashing the great white shark Chompy. But they seemingly refuse to leave.
They are noticeably absent at the ending, having apparently fled the beach before the barge could arrive.