The Pinnacles are the underwater continuation of Cape Woolamai's pink granite, a cluster of steep-sided towers standing on a rocky floor at 38 m and reaching to within 9 m of the surface about 1.5 km off the cape. Visit Bass Coast describes them as two vertical spires; Scuba Doctor records a collection of large pinnacles, with a deep anchoring point and a summit that first-timers should sound for 15–20 m east of the main mark. Either way the topography is the attraction.

The faces are close to vertical, split by chimneys and ledges, and because the site sits in clear Bass Strait water washed by Western Port's tidal outflow every surface is covered in colour: yellow zoanthids, orange and purple sponges, soft corals, sea whips and jewel anemones, with the deeper ledges carrying gorgonian fans. The bommies concentrate fish. Schools of butterfly perch, sweep and bullseyes hang off the walls, boarfish and morwong work the ledges, blue devils sit in the cracks, and there are enough crayfish in the deep base ledges that the site is also listed as a cray reef.

Australian fur seals from the Cape Woolamai haul-out often visit divers on the summit, and in autumn kingfish and the odd sunfish pass through. Depth makes this an advanced dive – the summit alone is a comfortable 9–20 m circuit, but the character of the site is in dropping down the faces to the sand and working back up, which puts most profiles in the 25–35 m range and demands attention to gas and NDLs in cold water. The Pinnacles is generally considered the best scenic dive on Phillip Island and one of the best granite pinnacle dives in Victoria, comparable to the Prom's offshore islands but reachable in half an hour from Newhaven.

Its limitation is weather: the cape takes the full Bass Strait swell and the bar at Newhaven has to be crossed twice.

Launch at the Newhaven boat ramp (Beach Crescent, Newhaven, immediately north of the Phillip Island bridge; sealed multi-lane ramp, jetty and large trailer park) and run south through The Narrows, across the entrance bar and around Cape Woolamai – about 7 km and 20–30 minutes in a fast trailer boat, longer if the bar is working. The entrance bar and the rip off the cape must be crossed near slack or on the flood in small swell. San Remo also has a ramp but is exposed to the same bar.

Sound for the summit at about 145° 20.24' E and anchor with a plough or sarca anchor in the deep sand on the down-swell side so the line stays clear of the rising rock.

Fully exposed to Bass Strait. The site is undiveable in any south-westerly or southerly swell over about 1.5 m and in fresh winds from the south or west; look for a period of northerly or light easterly winds and a swell under 1 m. The cape sits in the outflow of Western Port, so tidal streams run over the pinnacles; Scuba Doctor lists it as diveable on slack water (flood or ebb) and on the running tide by experienced divers, but plan the descent for slack and expect flow to build through the dive.

The Newhaven entrance bar limits boat access when swell and ebb combine. Summer and autumn give the most settled windows; winter offers the best clarity on rare calm days.

Descend the anchor line to the summit at 9–12 m, then drop down the up-current face to the sand at 30–38 m if certified and gas allows, checking the base ledges for crayfish and the soft-coral walls on the way. Turn at a third of gas or a planned NDL and spiral back up the pinnacle, spending the second half of the dive in the 15–20 m band where the sponge cover and fish schools are densest. Return to the anchor line for the ascent and hang a safety stop on the line or under an SMB; do not surface free in the flow.

Base at 38 m is within recreational deep limits but Scuba Doctor rates it Deep/Technical; EAN32 useful for the 20–30 m band. No overhead.

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.

Dive Victoria Group and Melbourne clubs schedule The Pinnacles on calm-weather Phillip Island trips a few times a year.