Pyramid Rock is a striking pyramid-shaped rock formation off the south coast of Phillip Island, with reef diving around its base out to about 18 m. The site is fully exposed to south and south-west swell and only fishes when conditions are settled, but when it lines up the diving is sensational — kelp-covered bommies, sponge gardens, crayfish, abalone, blue devils, weedy seadragons and big schools of sweep moving through the gutters. The pyramid itself is a navigation landmark you can surface near to orient yourself. Boat access from the Cowes or Newhaven ramps. Best on light northerly to north-east winds, swell under a metre and tide near slack. Use the live 7-day wind and swell forecast on this page to plan. Advanced divers — exposed open coast, current on the rock corners, surf wraps in around the formation if there's any south swell up.
How far you can see underwater — measured in metres. 10m+ is great, 5–10m is workable, under 3m is murk. Driven by wind, swell, and recent rain.
Long-period waves rolling in from the open ocean. Direction matters more than height — a S swell hits Portsea hard, but an E swell rolls past. Period over 12 s = real ocean punch.
Offshore (N or NE) flattens the surface and clears the water. Onshore (SE through SW) chops it up and stirs sand. Calm or light offshore is the magic combo.
This site faces the open ocean. The exposure caption above shows which directions slam in. Anything from the opposite side gets blocked — that's the safest window.
Slack water — the 30 minutes either side of high or low — is calmest and clearest. Mid-tide brings the most flow. Plan to be down at slack, up before the run picks up.
Bass Strait sits 14–16 °C autumn–winter, 17–19 °C summer. Below 16° a 7 mm hooded keeps you warm for 60 min+. Drysuit if you're going long.