Kayaking/canoeing, dinghy sailing and windsurfing
Prerequisites: aged eight or above and able to swim 50 metres.
Where: for beginners, Stanley Main Beach Water Sports Centre is the perfect place to pick up any of these water sports. It faces Tai Tam Bay, which has calmer sea conditions in summer, as it's sheltered from southwesterly winds and waves by the Stanley Peninsula. The more advanced will prefer St Stephen's Beach Water Centre, on the Stanley Peninsula. Facing southwest and overlooking Lamma Island, Stanley Bay is battered by gusts of southwesterly wind in summer.
Find out more: details of training courses and equipment hire on the Leisure and Cultural Services Department website, www.lcsd.gov.hk/watersport 
Prerequisites: aged 10 and above, able to swim 200 metres and comfortably maintain buoyancy for 10 minutes without any swimming aids. Green light from doctor.
Where: Shelter Island, Sharp Island, Chek Chau, Ninepin, Tung Ping Chau, Hoi Ha, Crescent Island and Pak Lap Tsai are some of the best diving sites, according to the Hong Kong government website.
Find out more: Hong Kong Underwater Association, www.hkua.org.hk 
Prerequisites: none; a game for everyone.
Where: Discovery Bay, Gold Coast, Tai Long Bay (Ham Tin and Tai Wan), Shek O, and Lower Cheung Sha.
Find out more: Hong Kong Ultimate Players Assoc, www.hkupa.com 
Prerequisites: guts and competent swimming ability.
Where: according to the website of Hong Kong extreme sports shop and event organisers X Game, the popular spots are Big Wave Bay and Tai Long Wan. As the peak surfing season is winter, the best chance to catch a wave in summer is before or after a typhoon - but it could be risky. X Game suggests Cheung Sha or Pui O for summer surfing, but check that the southwest wind is force four to five before heading there, or the waves will be too small.
Find out more: there is a Hong Kong Surfing Association, though it has no known website. Your best bet would be to search internet forums.