Kurnell Monument

Kurnell Monument: Sheltered Seadragon Shore Dive

By ScubaDownUnder Team · 2026-10-15

Behind the bronze whales on the rock platform at Commemoration Flat, a small inlet opens onto the sheltered water of Botany Bay. Divers ease in here, fin 10-15 metres out and sink down, and within a couple of minutes the reef drops over a wall onto sand at about 12 metres. There is no giant stride, no plunge into blue water and rarely any current worth the name. The Monument is a dive for slowing down: a long, close-focus prowl along a reef edge where weedy seadragons hang over the sand, anglerfish lurk among the sponges and almost every sponge-covered rock carries its own population of nudibranchs.

Sydney divers have called it The Monuments for decades, after the monument and flagpole that overlook the entry, and its reputation rests on two things: seadragons and shelter. When a big southerly is running, this bay-side stretch of Kurnell is one of the few protected dive sites in Sydney.

The site lies on the southern shore of Botany Bay in the Kurnell area of Kamay Botany Bay National Park, just west of Inscription Point and the entry for The Steps. This is nationally heritage-listed ground. In April 1770 the Endeavour sailed into the bay and Lieutenant James Cook's crew came ashore at Inscription Point, beginning the encounter between the British and the Gweagal, the northernmost clan of Dharawal speakers. Cook's men caught so many rays that he first named the bay Stingray Harbour. For the 250th anniversary in 2020, three bronze sculptures were installed along the foreshore, and one of them, The Whales, now marks the dive's entry point.

After a short surface swim, divers descend and head north or north-north-west, reaching the sand edge in about two minutes where a decent wall drops to around 12 metres. Off its base sit small boulders and large rocks dressed in sponges, sea tulips and small gorgonians, with kelp crowding the rock in between. From here the dive goes one of two ways.

The classic route runs west as a one-way drift on the incoming tide. The wall heads almost due west, one to three metres high, with the sand at 12-14 metres. After about half an hour it peters out, and a minute's swim south picks up a second, more prominent wall, a consistent three metres high and undercut with overhangs so large that veteran Sydney diver Michael McFadyen calls some of them caves. Large cuttlefish and schools of catfish shelter inside as the depth eases up to around 10 metres. When this wall fades after 40-45 minutes, nine or ten minutes' swimming south reaches a shoreline with plenty of easy exits, or divers can carry on across seagrass where small cuttlefish, large flathead, sea hares and pipefish turn up.

The alternative is an out-and-back to the east, usually dived around high tide or when there is little change in water height. Turning right at the sand, divers follow a small wall fronted by large boulders, then smaller boulders with very good sponge life, all at 12-13 metres. McFadyen finds seadragons more common on this eastern leg, and the return, run a little shallower along the reef, is where he has most often found anglerfish. Abyss Scuba Diving describes a sloping wall decorated with colourful sponges, and that is the lasting picture: a gentle reef margin, no deeper than about 14 metres.

Weedy seadragons are the headline. They favour the small bays of sand along the reef edge and the gaps between larger boulders, moving so slowly that they are easy to overlook. The weedy is the only seadragon in NSW waters, growing to about 45 cm and feeding on tiny mysid shrimps, and since July 2004 it has been an offence to collect or possess one without a permit. In late winter and early spring, look for males carrying eggs: on one October 2006 dive McFadyen counted nine dragons, seven of them pregnant males. In 2000, Spanish researcher Jaime Sanchez Camara tagged 90 seadragons at Inscription Point and The Monuments, when their range was thought to be about 100 metres, and in December 2004 one was found at Bare Island, more than 1.3 km away across the bay. Realistic hopes help: McFadyen reports far fewer dragons in recent years, which he links to dredging for the port expansion, an electricity cable and a water pipe, along with the huge rainfall of 2022.

Since about 2015, Bare Island anglerfish and sometimes painted anglerfish have appeared on the reef. The sponge-covered rocks hold nudibranchs of many species alongside giant jelly, magnificent and blue-throated ascidians, lace coral, sea fans and tube worms. Common stingrays, flathead, pygmy leatherjackets, moray eels, old wives, luderick, sergeant baker, eastern blue groper and wobbegong sharks fill out the cast. Rarer visitors here have included grey nurse sharks and, in June 2006, a hawksbill turtle just off the wall.

Visibility is the site's weak point. McFadyen rates five to seven metres as especially good here, although he has had 20 metres a number of times. An incoming tide brings marginally clearer water, and Abyss notes that visibility can deteriorate around low tide. Sydney-wide, his records show winter delivering the best visibility and October and November the worst. His log of more than 2,200 Sydney dives averages about 15.7 °C in August and September and 19.7 °C in March and April. Abyss recommends a 7 mm wetsuit or drysuit with hood, gloves and boots in winter, and a 5 mm suit is typically adequate in summer. Tidal flow is gentle, never strong enough to dictate the plan. Swell decides the day. The Monument is especially good in strong southerly winds and seas, and even very large southerly and south-easterly swells usually leave it diveable. Seas from the north to east quarter above 1-1.5 metres cause problems, and Abyss warns that east to east-south-east swell can wrap into the neighbouring Sutherland Point entry. Heavy rain can drop Sydney visibility below 2 metres in affected areas, so plan around recent rainfall as well as swell.

Photographers should bring a macro lens. Pygmy pipehorses live in the reddish weed covering many of the rocks and are very hard to find. McFadyen's images from the site include blue-lined bubble shells, Bennett's hypselodoris, purple-lined nembrotha and a dwarf firefish, and his page carries a detailed underwater map of the Kurnell sites by Marco Bordieri. He also rates it a great night dive, but the vehicle gates close each evening, so night divers walk about 800 metres along the foreshore from the corner of Captain Cook Drive and Prince Charles Parade. Confirm after-hours access with NPWS first.

Where The Leap is an advanced giant-stride drift with walls to about 22 metres and Voodoo belongs to the peninsula's exposed ocean coast, the Monument is the gentle, sheltered end of the Kurnell range, ideal for two dives and a long surface interval on the grass.

There is something fitting about diving slowly here. Joseph Banks and Daniel Solander, the Endeavour's naturalists, never looked deep enough into this bay to find its seadragons. A dive at the Monument rewards the attention they could not give it: a few hundred metres of reef edge, an hour of patient searching, and the quiet thrill of a seadragon materialising out of the kelp.

Site Access and Logistics

Follow Captain Cook Drive into Kurnell, turn left at the T intersection, take the next right into Cape Solander Drive, then turn left and follow the signs to the Commemoration Flat picnic area, which has parking, toilets, showers and drinking water. The shore entry is the small inlet behind the whale sculpture, with an alternative about 75 metres east on flat rocks. Exit at the entry after the eastern out-and-back, or anywhere along the shore at the end of the western drift.

The Kurnell area gates open 7am to 7.30pm all year, and entry costs $8 per vehicle per day (coin and card machines, or the Park'nPay app). Through 2026 the Kurnell Visitor Centre precinct, including its car park, is fenced off for construction, and a boardwalk lookout is being built beside the whale sculpture, due for completion in October 2026, so check the NPWS local alerts before you go.

Open Water certification is the minimum, and the rock entry makes a guided first visit worthwhile. Abyss Scuba Diving in Ramsgate runs guided shore dives from Friday to Sunday with Monument on its Kurnell rotation.

Sources

- Michael McFadyen's Scuba Diving: The Monuments - Michael McFadyen's Scuba Diving: Visibility and Wave Averages in Sydney - Abyss Scuba Diving: Sydney Dive Sites Guide - NSW National Parks: Kamay Botany Bay National Park Visitor Info - NSW National Parks: Captain Cooks Landing Place - NSW DPIRD: Syngnathiformes (Seahorses, Seadragons and Pipefish)

Header photo: A weedy seadragon (Phyllopteryx taeniolatus) in Sydney, by Taso Viglas, CC BY 2.0, via Wikimedia Commons.