LOS ANGELES - In California, repeated heat waves have sent Americans running to the beaches to seek relief, but more and more swimmers are finding themselves in troubled waters as strong waves whip the coast and fuel powerful rip currents. Last weekend, lifeguards in Los Angeles County performed a record 1,950 ocean rescues -- numbers that lifeguard captain Pono Barnes called "staggering." Since the start of July, California has been at the mercy of successive searing heat waves, with the mercury sitting at 30-35C, and even hotter inland. On several beaches, waves are at times 1.8m high. It's a dream for surfers, but can quickly become a nightmare for inexperienced swimmers thrashed by strong currents.