Rye Pier is the most-dived site on the Mornington Peninsula and one of the busiest shore dives in Australia, which says a great deal for a 500 m timber pier over a sandy bottom that never exceeds 7 m. What makes it special is the density and accessibility of its animals. The Scuba Doctor calls it perhaps the easiest place in the world to see seahorses, and big-belly and short-head seahorses can be found gripping the pylon growth within metres of the landing.

The pylons themselves are thick with sponges, ascidians and hydroids; tyres and debris on the sand shelter octopus of four species – Maori, southern sand, southern keeled and the blue-ringed – as well as decorator crabs, hermit crabs, bobtail squid, stargazers, puffers and nudibranchs. Smooth stingrays, often very large, cruise the sand and are fed by anglers at the head; giant cuttlefish appear in winter; Australian fur seals from Chinamans Hat occasionally visit; and in late May and June tens of thousands of giant spider crabs pile up around the pier on their annual moult, an event that draws divers, photographers and television crews from around the world. Sixty metres north of the head, Elsa's Reef is a small artificial reef of concrete and pipe in 6–7 m marked by pickets, usually with a large octopus in residence and juvenile fish sheltering around it.

For snorkellers the Octopuses Garden Marine Trail runs 200 m along the pier root with photographic signs on the pylons, seven out on one side and seven back. Night dives are the pier's best form: squid, cuttlefish, octopus and rays all emerge, and visibility is often better than by day. The pier was partly rebuilt in 2022, when the inner 270 m was closed to diving for most of the year.

Rye suits every level – it is where thousands of Victorians did their first open-water dive – and it rewards patience and a torch far more than fins and depth.

Rye Pier is on Point Nepean Road (B110) in the centre of Rye, 95 km from Melbourne via the Mornington Peninsula Freeway and about 4 km east of The Scuba Doctor dive shop. Park in the large foreshore car park beside the pier – plentiful in winter, crowded in summer – and gear up at the car. Walk the pier (500 m) to the lower landing about 50 m from the end and enter there, or enter from the beach beside the pier root and swim out along the pylons; the eastern side of the root has a pathway with handrails that makes beach entry and exit easier.

Exit at the landing or the beach. The Octopuses Garden snorkel trail starts at the beach on the western side.

Rye Pier is blown out by strong northerly winds, which put a chop straight onto its north-facing head and drop visibility to a metre; The Scuba Doctor's limits are roughly northerly, westerly and southerly under 15 knots and easterly under 25 knots. The ideal is a southerly breeze with a high tide and glassy water. The pier is not current-prone but the shallow inner section is under a metre at low tide, so plan around high water.

Summer weekends bring swimmers, boats at the lower landing and jet skis, and visibility is at its worst; winter and night dives give the clearest water. Rain has little effect. Spider crab season (late May–mid June) coincides with the best winter conditions.

Enter at the lower landing, descend to 3 m and follow the pylons to the L at the head, then swim 60 m north across the sand to Elsa's Reef in 6–7 m, marked by pickets. Circle the reef, return to the pier head and work back along the opposite row of pylons toward shore, checking every tyre and pylon for seahorses and octopus. Finish along the snorkel-trail signs in 1–3 m; no formal safety stop is required.

The Scuba Doctor (Rye) runs guided shore dives and night dives here throughout the year; Bayplay (Portsea) guides snorkel and dive tours; Dive Victoria, Aquability, Diveline and Melbourne dive clubs use it constantly for training and spider-crab season dives. No charter needed.