My 'driving instructions' to friends trying to find NSW. Coming from Sai Kung.
Nam Sang Wai is easy to find if you know where it is and hard to find if you don't. Drive North up the Tolo Highway and exit at Junction 11 of Route 9, signposted Fairview Park. Take the 2nd exit of the roundabout and keep driving until you come to another roundabout. It is quite a long way, and you need to avoid the road going up the flyover. When you get to the 2nd roundabout you go all the way around and loop back the way you came but on the other carriageway obviously. Dangerous otherwise ;-)
NSW is the first exit on the left and is signposted.
When you turn off at the correct junction you need to work your way right along the river. It is a very long road and the drive to the bird photography site is about 5 minutes down the road and is marked, conveniently, by what is I think a blue portaloo thingy. You can pull in there. Lots of parking space. People photograph from the wall or climb over and shoot from the slipway.