The Environmental Protection Department released the latest grading of water quality of 33 beaches open to the public, rating 18 as 'good' and 15 as 'fair'.

Compared with the grading released last week, Kiu Tsui Beach has been upgraded from 'fair' to 'good' and Big Wave Bay Beach has been upgraded from 'poor' to 'fair'. Discovery Bay has been changed from 'good' to 'fair'.

The changes are generally within the normal range of fluctuation of the bacteriological water quality of the beaches, the department said.

Seven gazetted beaches - Anglers', Approach, Ting Kau, Casam, Gemini, Hoi Mei Wan and Lido - are closed to swimmers year round because of poor water quality.

People are advised not to swim at the closed beaches.

Beaches are likely to be more polluted than their grades suggested during and after periods of heavy rain. Bathers should avoid swimming at beaches for up to three days after a storm or heavy rainfall.

Visit the department's website or call the beach hotline, 2511 6666, for details.