There are quite a few different dives at the entrance to Botany Bay in Sydney's south. You can do numerous boat dives on the northern headlands and just to the south of the southern headland. For shore dives, you can dive the whole area around Bare Island and La Perouse on the north side as well as the Captain Cooks Landing Place section of Botany Bay National Park on the southern side.
One of the spots that is not dived all that often is the area to the south-east of The Leap. This is because you need really calm seas to get out of the water here. If there is a period of westerly winds and the seas are looking good, you can try this spot. Drive into Botany Bay National Park at Kurnell and drive up past Inscription Point and The Leap parking areas, you will see a very rough track off to your left. This leads to Yena Flat, a very primative parking area. It is not really a picnic area and is more popular with surfers and fishers than anyone else.
If the seas are really flat you will be able to see from here if the dive is possible. Have a look to the north of the car park (walk to the left of the bushes) and you will see an easy way onto the rock platform and down to the water's edge. There is a very good rock to drop into the water from here. You could also exit here as well.
Before gearing up, have a look out into the small bay to the east of the southern end of the car park. There is a sloping rock that is easy to come back onto. Check out the way back to the cliff edge to make it easier later on. It is an easy climb back up, much less strenous than Shiprock.
Once ready, walk to the northern entry point and get in the water. Swim out 10 metres before descending. The depth here is only five metres or so and the bottom is composed of large boulders. There are literally millions of fishing sinkers here, if you ever need any lead, this is where to get it. Head north-east (you could also go north I reckon - I will have to check this out).
After about three and a half minutes the depth will start dropping from six metres till at five metres you are at 10 metres. Here there is a wall that drops to 15 metres. This is composed of whitish/pink rock and there is a lot of kelp on the bottom with a little sand. This is not the reef edge proper. On my dive here there was a huge amount of fishlife in this area, mostly one-spot pullers, ladder-finned pomfrets and yellowtail.
Turn right and head east. The reef here comes up a metre or so before going back towards 16 metres. It stays around the 15 to 18 metre range till about the 20 minute mark. You will have been swimming mostly east, with some bits to the north a little and other sections to the south-east. There are small overhangs and some boulders. We saw a lot of Port Jackson sharks along here as well as one eastern blue devilfish in a small cave and one small horned shark.
At the 20 minute mark we came up a little and followed a shallower wall to the south-east. This gradually turned more to the south and we came across a very large cave at about 14 metres. There were lots of ladder-finned pomfrets in here. At 30 minutes we were heading almost south, but with a little south-west in it. We were still following a small wall which was gradually getting shallower, from about 14 metres at the start till at 35 minutes we were in eight metres.
We headed from here to the west and after a few minutes we were in five metres so I decided to check where we were. Bingo! Right off the planned exit spot. I went back down and we spent another 10 minutes or so in this general area before exiting.
A very nice dive, for all divers so long as you have someone with you who is good on navigation and reading entry and exit spots. You could also do this dive as a straight out to north and back again dive.