Jurien Bay is the only major breeding area for Australian sea lions on the west coast of Australia, and the sea lion snorkel at the islands and rocks off the town is the region's signature marine experience. Essex Rocks is one of the sanctuary zones of the Jurien Bay Marine Park, established in 2003, and one of the colonies visited by the local tour operators.

Australian sea lions are endangered, with only around 12,000 left, some 6,500 of them in Western Australia. They are endemic to WA and SA and breed on an unusual 17-18-month cycle. At the haul-outs off Jurien, young animals and females returning from feeding frequently approach snorkellers, twisting and somersaulting around them over the sandy bottom and seagrass in a few metres of clear water.

In-water encounters are only conducted by licensed operators under strict guidelines – snorkellers stay at least 50 m from the shore, never touch the animals and remain passive, and time with the animals is limited. Jurien Bay Oceanic Experience, operating since 1996 with marine-science-trained guides, supplies wetsuits and snorkel gear and provides GoPro footage; Sea Lion Charters uses custom-built boats to visit several colonies.

Beyond the sea lions, the surrounding reef has limestone ledges with sponges and a mix of temperate and tropical fish thanks to the Leeuwin Current, and dolphins are often seen on the way. The experience suits any confident swimmer, including children aged six and over with some snorkelling experience. It is a snorkel, not a scuba dive.

Jurien Bay is about 220 km (2.5 hours) north of Perth via the Indian Ocean Drive. Tours depart from the Jurien Bay Boat Harbour (Breakwater Drive). Jurien Bay Oceanic Experience runs 2.5-hour sea lion interaction tours and Sea Lion Charters runs similar trips; the run to the colony takes 15-20 minutes.

Snorkellers stay in the water at least 50 m from the shore of the haul-out, and interaction time is limited (about 45 minutes maximum).

The Turquoise Coast is protected by a line of offshore limestone reefs and islands that break the prevailing south-westerly swell, creating a lagoon of calm, clear water inshore. The main enemy is wind: the strong southerly sea breeze ('Fremantle Doctor') blows most summer afternoons from about 11 am, and winter north-westerly fronts bring storms and poor visibility. Mornings from October to April are best.

Sea lion tours run in most conditions except strong winds and large swell; the sanctuary islets are exposed to the south-westerly sea breeze, so tours generally depart in the morning.

Enter from the tour boat in the lee of the islets, float quietly in 3-6 m over sand and seagrass and let the sea lions approach; follow the guide's directions and keep at least 50 m from the shore.

Jurien Bay Oceanic Experience (Jurien Bay Boat Harbour; est. 1996) – daily sea lion snorkel tours, reef snorkel tours, PADI courses and dive charters; Sea Lion Charters (Jurien Bay Boat Harbour) – sea lion snorkel tours to several colonies. Both run daily in season (roughly September-May), weather permitting.