Snorkeling Byron Bay Julian Rocks

Julian Rocks rises 200 metres from the seabed three kilometres off Cape Byron, its twin volcanic remnants marking the convergence of warm tropical currents from the north and cold nutrient-rich flows from the south.

This collision of waters transforms Nguthungulli—the rock's Aboriginal name meaning 'father of the world'—into one of Australia's most biodiverse underwater sites, where 1,000 fish species and seasonal megafauna share territory across submerged caves and swim-throughs.

The Arakwal people held the formation sacred for millennia before European sailors charted it in 1770. Cook's crew named the twin peaks after the Julian calendar, unaware they were documenting a submarine mountain that would later shelter grey nurse sharks in numbers unmatched anywhere on the east coast. Protection arrived in 1982 when the New South Wales government declared the site a marine reserve, prohibiting fishing and anchoring within 400 metres of the rocks. Today Nguthungulli sustains populations that have collapsed elsewhere: leopard sharks nest in the gutters between boulders, loggerhead turtles drift through thermoclines, and manta rays spiral above the northern pinnacle during summer months.

Visibility at the reserve fluctuates between 10 and 30 metres depending on offshore winds and plankton blooms. The eastern side drops to 24 metres in a wall pocked with overhangs where wobbegong sharks lie motionless against volcanic basalt. Soft corals and sponge gardens coat the shallower western slope, where schools of kingfish and trevally hunt in coordinated formations. Between June and November, humpback whales pass within sight of the rocks during their annual migration, occasionally breaching close enough that snorkelers surface to dorsal fin slaps echoing across the bay. Certified operators now run multiple departures daily, maintaining a strict code that prohibits touching marine life or entering the caves where nurse sharks aggregate. Water temperature holds between 19 and 24 degrees year-round, warm enough that most snorkelers wear only a spring suit or rash vest during the Byron Bay snorkeling season.