Cape Woolamai Reef is the dive under the cape itself, where the pink granite that forms the highest point on Phillip Island continues into the water as towering columns, massive boulders and swim-throughs, in the words of the Scuba Doctor listing, which calls the terrain awesome. It is a simpler and shallower dive than The Pinnacles offshore, sitting at 12–15 m on the Cleeland Bight side of the cape, and for that reason is often the first dive of a Phillip Island boat day or the fallback when swell rules out the outer sites. The layout is a jumble of house-sized granite blocks fallen from the cliff, leaning against one another to form short tunnels, caves and overhangs, with sand and cobble channels between them.

The upper faces carry kelp and coralline algae; the shaded undersides and swim-throughs are lined with encrusting sponge, zoanthids and ascidians, and the deeper ledges at the sand line hold crayfish. It is historically an abalone and cray reef, and blacklip abalone are still noticeably large here; take limits apply and a Victorian recreational fishing licence is needed to collect anything. Port Jackson sharks are the reliable resident, resting under ledges in winter and spring, and the fish life is described as pretty good: wrasse, morwong, sweep, leatherjackets, old wives and boarfish.

Fur seals hauling out on the cape's southern rocks sometimes swim round to investigate. Gull Island (Bird Rock) sits 800 m north in the same sheltered bay and makes a natural second dive. Cape Woolamai Reef suits Open Water divers in calm conditions and photographers who want granite scenery without the depth of the pinnacles; it also gives a strong impression of the scale of the cape, which rises 110 m directly above the boat.

Launch at Newhaven boat ramp (Beach Crescent, Newhaven) and run south through The Narrows and down Cleeland Bight to the cape, about 5 km and 15–20 minutes. Because the reef is on the eastern, bight side of the cape it can often be reached without crossing the open bar, but the Narrows still run hard and should be transited near slack. Anchor in sand off the boulder line in 12–15 m.

Shore access is not practical: the cape is a Phillip Island Nature Parks reserve with a shearwater rookery, and the walking track ends on 100 m cliffs above the site.

More sheltered than The Pinnacles because it sits in the lee of the cape from south-westerly swell, but it is still open to the south and east; a southerly or south-easterly swell over 1.5 m or a fresh easterly wind makes it surgy and unsafe close to the rocks. Best on a northerly or westerly wind with swell under 1 m. Tidal flow along the cape can be noticeable, so plan around slack in The Narrows for the boat transit and expect some current on the reef at mid-tide.

Diveable year-round; visibility is best after several days of settled weather and worst after big south-westerly blows stir the bight.

Anchor in 12–15 m off the boulders and descend the line to the sand. Work along the base of the granite towards the point, using the boulder swim-throughs and overhangs, keeping the rock on one shoulder. Turn at half gas or when current builds, come back along the top of the boulders at 8–12 m where the kelp and abalone are, and finish under the boat.

Safety stop on the anchor line.

No dive shop or dedicated dive charter is based on Phillip Island. Sites are dived by Melbourne clubs (VSAG, Melbourne University Underwater Club, Frankston/Peninsula clubs) and private boats launched at Newhaven or Rhyll; Mornington Peninsula shops (Dive Victoria Group, Portsea; The Scuba Doctor, Rye) run occasional Phillip Island days. Ocean Adventures Phillip Island (Cowes) runs seal-snorkel tours only.