The water off Crowdy Head has been amazingly cold - it seems to have been stuck around 16 deg since I first looked at the Manly Hydraulics Lab site about 2 months ago, apart from a couple a brief excursions towards 19-20. If I visit the area I don't think I'll be swimming in the ocean.
It would be interesting to see what the weather has been like at places like Harrington. Possibly often cool and foggy like Syndey beaches in early November? The nearest NSW 'coastal' stations shown on the BOM site - Taree Airport & Port Macquarie Airport - are some distance inland.
Sydney waters seem to have settled at their seasonal average of about 22 deg. I expect this means that sunny days with no strong general wind circulation will max out at a seasonal 24 - 26 deg near the coast.