Cape Otway is the southern tip of the Otway Ranges and the start of the Shipwreck Coast — this stretch of water has claimed dozens of vessels over the years and many of the deeper wrecks lie in around 35 m of Bass Strait water off the cape. Wreck life is rich: marine growth, schools of bullseyes, blue devils, banjo sharks, snapper, plus pelagic visitors. At 35 m these are advanced wreck dives with short bottom times. Boat access only, generally on charter from Apollo Bay or Port Campbell. Best in light north-east winds with swell under a metre and tide near slack. Use the live 7-day wind and swell forecast on this page to plan. Advanced wreck-trained divers only — depth, current, exposed open coast, several kilometres offshore, plan around a properly settled forecast and have a back-up site in mind if conditions deteriorate.
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.