From the Spit Bridge you have the choice of paddling around to Balmoral Beach, or into Middle Harbour, a less well known and visited part of Sydney Harbour. Just dodge the yachts, though.
Catch the bus to Manly and get off at the Spit Bridge.
www.sydneyharbourkayaks.com.au/index.asp
+61 (0) 2 9960 4389
Google map: