The Whale Watching Rockfall is the southern companion to the Whale Watching Platform site on Cape Solander, and McFadyen rates it just as highly – one of the most interesting spots in Sydney and worth diving many times. From the surface the landmark is a very obvious rockfall on the cliff a little south of the platform. Underwater, a rocky bottom at 19–20 m with some sand patches leads to a quite sheer wall facing west and dropping from 12–13 m, with large boulders piled below it.

Features come thick and fast: a swim-through just off the wall, a large but low cave, and a bigger cave that divers can swim completely through. The most unusual feature is a series of round and figure-eight shaped holes worn into the rock, like large bathtubs. Heading south there is a small wall to drop over to 21–22 m and the bottom continues down to about 25–26 m, making nitrox worthwhile.

The wall carries sponges, sea squirts and a few small gorgonians. Fish life is excellent, with eastern blue devilfish in the caves, Port Jackson sharks in season, large schools of yellowtail and one-spot pullers, many species of leatherjackets and numerous cuttlefish. Sightings logged here include a juvenile Moorish idol (a tropical stray carried down by the East Australian Current), nudibranchs, a moray eel and a pygmy pipehorse, which shows the macro potential for divers who look closely.

Visibility is typically 12–15 m. As with the rest of the Kurnell coast there is no regular charter, so it is a private-boat or club dive, 15–20 minutes from the Botany Bay ramps. The site suits Advanced divers comfortable with caves and navigation who want something different from the crowded shore dives inside the bay.

Boat only – the Kurnell cliffs are sheer and in Kamay Botany Bay National Park, with no practical shore entry. From Botany Bay, launch at Kyeemagh (Cooks River), Foreshore Road or Bonna Point (Silver Beach, Kurnell), run out past Captain Cook's Landing Place, Inscription Point and The Leap, then turn south along the cliffs; from Port Hacking (Gunnamatta Bay/Tonkin Park or Lilli Pilli ramps) run out past Bass and Flinders Point and north-east along Bate Bay past Cronulla Beach and Cape Baily. About 15–20 minutes from the Botany Bay ramps: head south past The Leap to the whale-watching platform on Cape Solander, then position a little south of the platform and run in towards the rockfall on the cliff, which is very obvious.

McFadyen's GPS is 34° 01.1232' S 151° 13.9702' E; anchor where the depth comes up from 22 m to 18 m.

The Kurnell cliffs face east to south-east, so they catch north-east, east and south-east swell; plan on seas under about 1.5 m. Being close to the Botany Bay entrance, visibility drops on the ebb when dirty bay water flows out, especially after rain – dive on a high or incoming tide. Like the platform site next door, it is exposed to south-east swell wrapping around Cape Solander and to easterly seas, which surge through the caves and holes.

McFadyen averages 12–15 m visibility here and has had 15 m at low tide after heavy rain, though a strong ebb from a dirty bay will reduce it. Best on calm winter westerlies; summer north-easterlies make afternoons rough.

Descend to 19–20 m and head north along the wall past the swim-through and the first low cave to the larger cave you can swim right through; at the corner turn right over boulders onto flat rock, explore the western wall, then go south through the crack beside a large boulder, dropping over the small wall to 21–22 m, and back to the anchor. Nitrox extends time for the 25–26 m sections to the south.

No regular charter – private boat or dive-club (St George Scuba Club) only