Number 16 Beach is one of the numbered ocean beaches on the Rye back-beach stretch, opening onto Bass Strait. The reef runs out to around 14 m and is a solid kelp-and-sponge bottom holding crayfish, abalone, weedy seadragons, blue devils and the occasional school of bullseyes in the cracks. Shore entry from the beach steps means surf zone work, so you need a flat day — south swell shuts the site down fast. Best in light northerlies, swell under a metre and tide near slack. Plenty of parking up at the cliff top, then a fairly steep stair walk down. Use the live 7-day wind and swell forecast on this page to time your dive. Intermediate divers only — surf entry, exposed south-facing coast, weight up properly and don't dive it on big spring tides if the swell is over a metre.
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.