As the swimming season comes to a close, the water quality at five beaches has improved. Figures released yesterday by the Environmental Protection Department see Big Wave Bay and Shek O upgraded from poor to fair. Water quality at Trio has gone from fair to good. Casam and Gemini beaches have improved from very poor to poor. But Tong Fuk was down from good to fair and Cheung Sha Lower was down from poor to very poor. Hong Kong South: Big Wave Bay, fair; Chung Hom Kok, good; Deep Water Bay, good; Hairpin, fair; Middle Bay, fair; Repulse Bay, good; Shek O, fair; South Bay, good; St Stephen's, good; Turtle Cove, fair; Stanley Main, fair. Tuen Mun District: Golden Beach, poor; Old Cafeteria, poor; New Cafeteria, poor; Kadoorie, poor; Butterfly, poor. Sai Kung District: Clear Water Bay 1st Beach, fair; Clear Water Bay 2nd Beach, fair; Hap Mun Bay, good; Kiu Tsui, good; Silverstrand, fair; Trio (Hebe Haven), good. Islands District: Cheung Sha Upper, good; Cheung Sha Lower, very poor; Discovery Bay, fair; Hung Shing Yeh, good; Kwun Yam Wan, fair; Tong Fuk, fair; Lo So Shing, good; Pui O, good; Silvermine Bay, poor; Tung Wan, Cheung Chau, good. Tsuen Wan District: Casam, poor; Gemini, poor; Hoi Mei Wan, poor; Lido, very poor; Tung Wan, Ma Wan, fair.