Dive
Shiprock point in Dolans Bay has a marine reserve. Some tropical fish can even be seen here in the summer months, when the water is warm in February mainly. You can see many fish varieties snorkelling along the rocks all the way around from Lilli Pilli point to Shiprock. Watch out for fishermen outside the reserve, and watch out for speedboats in the channel. Shiprock dive can hire equipment or do training courses.
Do the things there are to do in Cronulla and the Royal National Park and then:
Swim in the Port Hacking
The Port Hacking River lies along the Southern Boundary of the Sutherland Shire, and separates it from the National Park. The Port Hacking is a clean waterway, nice for swimming except for possibly the day after heavy rain. There are enclosures nets for swimming along the waterway, usually uncrowded. You can swim outside the enclosures if want to. The biggest threat is jetskis, sharks are very rarely seen. From Lilli Pilli Point, there is a large sand spit you can swim out to at low tide. There are some little sting rays out there that can sting you if you tread on them. It hurts, but it not otherwise dangerous.
Kayak on the Woronora
The Woronora is a easy river for kayaking or canoeing for an hour or whole day. Boat traffic is slow, and the river is usually protected and calm. In an hour you can kayak from the boatshed up to the Woronora Bridge or vice-versa. For a longer trip if you are fit you can go all the way up to the Needles, which is really the limit of navigation of the river, and a nice swimming spot. You can hire a kayaks everyday from Woronora Boatshed. Prices are $15 for the first hour, and $10 for each hour after that. There usually is no requirement to book. , and explore the many inlets around Bonnet Bay, or if you are fit, even go upstream to the needles. Take sunscreen, covering clothing, and a hat.
Star Boatshed
Hires kayaks, dingies, canoes. Has coffee and milkshakes