As Australia’s largest city it is a place that most Australians, or visitors to Australia, eventually visit. It is also one of Australia’s largest natural harbours, with a heavily populated estuary that is still in surprisingly good condition. This has a lot to do with the clean ocean waters that flush the outer harbour and coastline, creating moderate to good diving conditions. Sydney’s waters are also relatively warm and are also rich in varied marine life, sitting as it does in a mixing zone between temperate and sub-tropical waters.
The sheltered bays of the harbour offer protection from the wind and have some good shallow diving on sediment bottoms that are renowned for rare and interesting small marine life. It a macro photographer’s paradise except for the curses of all urban dive spots, too many boats, heavy car traffic and the dreaded parking meter attendant. This all just heightens the sense of escape once you are in the water. Sites like Shiprock, Lilli Pilli, Camp Cove, Parsley Bay and Clifton Gardens can be dived in almost all weather conditions. They can experience very poor visibility if there has been heavy rain during the week.
Most of the diving is done on the open coast of the eastern suburbs. Here the fresh ocean water creates clearer conditions and attracts more fish life. The drawback is the exposure of these sites. Any winds over 15 knots from all but the west or north-west will rule out boat diving. Any onshore winds over 10 knots, or heavy swells, will make most coastal shore diving sites unsafe. Sites more sheltered from southerly wind include Shelly Beach, Fairy Bower and South Maroubra, Bare Island Right, Inscription Point and The Monuments. Boats dives will be limited to the lee of the Sydney Heads and Botany Bay. Northerlies are the worst with only Bare Island and Bass and Flinders being worth a look. Some boat diving can still be done, but over 15 knots most sites are precluded.
The glorious days are after a couple of days of westerly weather followed by light winds. These days are most common in Winter, when the visibility also peaks. Visibility is at its worst in October and November. May to September has the lowest swells and still has water temperatures of 13-22 degrees Celcius, in summer it will peak at 24 degrees.
The north shore of Sydney is about glorious beaches and swank cafes. Its offshore reefs are frequently visited in good weather and offer great fish life. Some of these are kilometres offshore. There are also a number of interesting shipwrecks. The rocky reef along this section of the shore is only narrow and sandy, but there are also a couple of reasonable shore dives. The south side offers a very broad variety of diving along the coast, on offshore reefs and in the nearby sheltered areas of Botany Bay. Although the north shore is popular, most of the diving effort is focussed in the south around Botany Bay. There are also a variety of man-made sites from wrecks to wharves and artificial reefs. For technical divers, there are also a number of very deep depths off the harbour, many yet to be discovered.