This article was originally published in Nature NSW

Botany Bay was originally named Stingray Harbour by Captain Cook when he first landed here in 1770. Cook later renamed it based on “the great quantity of plants Mr Banks and Dr Solander found in this place”. Had Cook been able to strap on a SCUBA tank and mask, he might have remarked that the botanical and zoological wonders of this large bay don’t stop at the water’s edge. Today, a diver can explore these waters and see reef formations and marine animals found no-where else in the world.

There are many interesting sites at the entrance to Botany Bay, including Henry Head, The Leap and Cape Banks, but in this article we will focus on the two most accessible; The Steps at Kurnell and Bare Island at La Perouse. These correspond with the southern and northern headlands of Botany Bay, respectively.

The Steps is accessible from Solander Dr in Kamay Botany Bay National Park. There is a small carpark from which a set of steps descends to the rock platform where the dive starts and finishes. An alternative dive is to enter further south at The Leap and drift with the incoming tide to The Steps.

The Steps has a range of interesting sponges, ascidians, kelp beds and soft corals, but the real attraction is the possibility of seeing Weedy Seadragons. These live in 10-20 m amongst the kelp and along the sand-line where they feed on mysid shrimp. Anecdotally, the population here is diminishing however there are still several animals to be found. This year in summer there were several males with eggs; a hopeful sign for future viability of the population.

Bare Island, on the north side of Botany Bay, is one of the most popular dive locations in NSW. There are four dives here; the east side, west side, deep wall (south side) and a circumnavigation dive. The latter requires extra air (see “special equipment”) but it encompasses all of the other three dives.

It’s best to do the circumnavigation dive on the last hour of the incoming tide. Start on the mainland shore to the left of the bridge. Descend to the sand and swim south to the rocky reef of the island, and follow it around in a clockwise direction. After around 20 mins, take a bearing west and cross the reef, otherwise you’ll end up in the middle of Botany Bay at the bommie! Continue around to the west then north before exiting at the small ramp under the bridge.

Bare Island has several interesting marine creatures; most notably the Bare Island Anglerfish and Sydney Pygmy Pipehorse which are endemic to the local area, and Red Indian Fish which is found only in southern Australia. Nudibranches abound here; you are likely to see up to a dozen different species on a single dive, including blue dragons, splendids and Tasmanian chromodorids.

There are a few hazards to watch out for in Botany Bay; chiefly boat traffic and fishing tackle as it’s a popular recreational fishing area. Always carry a surface marker buoy in case you have to come to the surface away from shore. Currents can run strongly and may be a hazard at the tail end of the outgoing tide. Despite the hazards, Botany Bay is well worth the effort on a clear sunny day after dry weather, when you’ll get the best visibility. You might even see a species found nowhere else in the world!