(A number of the downwinders described below with SUP videos depended on boat transportation to and/or from islands. Also with human powered vessels, many if not all runs that cross shipping channels (Hong Kong has some of the world's busiest) require by law that you have safety boat accompaniment. Marine police will check you)
Ping Min Chau Run - 1.6km / 1 mile paddle from Lobster Bay to Ping Min Chau (island), and then a 3km downwind to the North East Corner of Shelter Island
Sai Kung northerly part of the New Territories of Hong Kong video
Port Shelter Express Run - Tai Mong Tsai Road Pier, Sai kung - Sheung Sze Wan Bay 10 km Downwindable.com, OC1 video
Frisky Whiskey Run - Sai Kung Country Park - Clear Water Bay Marina 14.5 km Downwindfun