Yowie Bay Boat Ramp is an unglamorous but interesting muck dive in one of Port Hacking's northern arms, and McFadyen's account captures its appeal: a night dive in a quiet suburban bay where bioluminescence made divers look like ghosts. The site is at the end of Wonga Road, where a public ramp leads straight into the bay. The depth at the end of the ramp is just over 7 m, and the bottom, a sandy mixture with some silt, drops fairly quickly towards 14 m.

To the east is a marina whose pylons carry little growth; visibility under it is often less than a metre, recovering to about 4 m in the shallower zones beyond. Further on, near moorings and pontoons, a submerged wall runs north–south at 4–6 m. Oddities on the bottom include a submerged station wagon and a huge pile of old beer bottles from about 1965.

The marine life is typical estuary muck fare: pufferfish, whiting, fan-bellied leatherjackets, mud crabs and blue swimmer crabs, cuttlefish, large prawns and a spotted eel, with a very large conger eel and a huge moray eel among the highlights. Visibility is best on a high tide, about an hour after Fort Denison, when it may reach 5–7 m in open water. Because boats use the ramp and marina, divers should listen for engines and stay down until they pass; compasses can be thrown off by the steel and engines above.

It suits experienced Open Water divers who enjoy muck diving, night diving and the unusual, and it is a useful option when the ocean is unworkable.

From Kirrawee or Gymea drive down to Yowie Bay and follow Wonga Road right to the end. Park in the angled spaces near the boat ramp; parking is usually easy, especially at night. Gear up at the car, walk down the ramp (very slippery with weed) and enter carefully.

Keep clear of boats launching and retrieving. Pro Dive Cronulla is about 15 minutes' drive.

Deep inside Port Hacking and fully sheltered from ocean swell and most winds – divable when everything else is blown out. Visibility is the issue: plan on a high tide, about one hour after Fort Denison high, when it can reach 5–7 m in open areas; under the marina it drops to less than a metre. After heavy rain the bay becomes very murky.

Weekend boat traffic makes night dives more pleasant.

Head east from the ramp, look under the marina (very low visibility), navigate towards the moorings and the shore near the pontoons, find the submerged north–south wall at 4–6 m, then return via the wharf to the ramp. Listen for boats and do not ascend until engine noise fades.

No regular operator – occasional St George Scuba Club night dives; independent muck divers.