Blue Devil Reef was discovered in mid-February 2009 when McFadyen was trying to relocate a different site and found this reef instead. It lies about a kilometre just south of east from the Port Hacking entrance, close to the Jibbon reef complex. Running in from the north, the sandy bottom at about 25 m rises to reef at 20 m and then 17 m.

The reef is oriented east–west. Its southern section has a small wall that curves around to the east, with small overhangs, and it links via the wall to a higher section of reef. Along the sand edge to the east, after 30–40 m, is a higher section of wall that carries a lot of sponges and sea squirts, with small overhangs and gaps between small rocks.

The name comes from the eastern blue devilfish living in the overhangs, one of the most attractive fish on Sydney reefs, and the gaps shelter a variety of other reef fish. Typical Port Hacking offshore species – one-spot pullers, silver sweep, yellowtail, leatherjackets and red morwong – are likely to be seen over the reef. The layout is simple: follow the wall north for about 50 m until it fades, or go east along the sand to the higher wall.

Bottom time is 25–30 minutes depending on how long divers stay deep. Like the other reefs outside Port Hacking, it has no charter service and is dived by private boats and the St George Scuba Club. It suits Advanced divers wanting a straightforward reef dive close to the ramps and is a good alternative when the fast-food reefs are occupied.

Boat only. Launch in Port Hacking (Gunnamatta Bay/Tonkin Park at Cronulla, Lilli Pilli or Bundeena ramps) and run out through the entrance; the Jibbon reef complex lies just east and south-east of Jibbon Bombora, 5–10 minutes from the ramps. From the entrance run just south of east for about 1 km.

McFadyen's GPS is 34° 04.4986' S 151° 10.6817' E. Run in over the reef from the north and anchor in about 20 m.

These reefs sit just outside Port Hacking, exposed to swell from the north-east through the south-east, with some southerly wrap past Jibbon Bombora; plan on seas under about 1.5 m. At 20–27 m they are below most surge once down, but anchoring needs moderate conditions. Water quality is good because the adjacent Royal National Park contributes little runoff, and visibility is usually 12–20 m; heavy prolonged rain can bring dirty water out of Port Hacking on the ebb.

Westerly and north-westerly winds give the best days.

From the anchor head north and follow the wall for about 50 m until it fades, or go east along the sand edge for 30–40 m to a section of higher wall covered in sponges and sea squirts. Allow 25–30 minutes depending on depth.

Nitrox (EAN28–32) recommended; bottom time on air about 22–29 min.

No regular charter – private boat or dive-club (St George Scuba Club) only; no charter boat currently operates out of Port Hacking.