South Bay Beach is one of a string of beaches located on the south side of Hong Kong Island and it is within walking distance of the neighbouring Middle Beach and Repulse Bay. It is, however, not served by public transport. It is located in a secluded bay facing the Ocean Park headland and has a good sandy beach. It has a bathing shed and raft, BBQ facilities, changing rooms, showers and a fast food kiosk. Lifeguard service operates from April to October. During the daytime at least, the beach is usually quiet and often almost deserted. However, the rooftop South Bay Club, has, in recent years, helped the beach earn its reputation as a “party beach”, being particularly popular with Hong Kong’s trendy youth at night time.
Taken from hongkongextras.com.
Note that it's a 4km walk from Repulse Bay. Please beware of life guard muggles at GZ.