Julian Rocks Marine Sanctuary

Julian Rocks Marine Sanctuary

By ScubaDownUnder Team · 2026-05-06

Three kilometres off Byron Bay's Main Beach, two weathered volcanic outcrops break the Pacific surface. Beneath them, in the meeting zone where the East Australian Current carries warm tropical water down past cooler southern flows, marine life converges in numbers and variety that no other site on the east coast quite matches. [Julian Rocks](https://www.scubadownunder.com/dive-sites/julian-rocks) is the dive that shapes Byron Bay's reputation as a diving destination: a short boat ride from town that delivers leopard sharks in summer, grey nurse sharks in winter, manta rays, turtles, and a supporting cast that runs from pygmy seahorses to passing dwarf minke whales. Locals and operators call it Julian's. The Bundjalung people have called it Nguthungulli for far longer.

Julian Rocks sits within a Sanctuary Zone of the Cape Byron Marine Park, declared in 2002 and one of the most strictly protected marine areas in NSW. No fishing, no spearing, no collecting of any marine life inside the zone. Beyond the protection, the site's reputation rests on geography: Byron Bay sits exactly at the latitude where tropical species reach their southern limit and temperate species reach their northern limit, producing a year-round overlap that few sites worldwide replicate. The Bundjalung name Nguthungulli refers to the creator being whose body, in story, formed the rocks themselves. Recreational diving here began in the 1970s, and the site has been continuously documented by operators and researchers ever since.

The two rocks rise from a shallow plateau at around 8 metres and drop on their seaward sides to 25 metres at their deepest. The terrain is broken volcanic basalt, sculpted by surge and current into the gutters, swim-throughs and overhangs that give Julian's its character. Most dive plans launch from the boat onto moorings on the western side, where a sand bottom at 12 metres anchors a reef structure that fans outward into named sub-sites. The Nursery is a sheltered shallow area where grey nurse pups gather in winter. Hugo's Trench is a deeper canyon on the southern face that drops past 22 metres. The [Cod Hole](https://www.scubadownunder.com/dive-sites/cod-hole) is a low-current swim-through favoured for first dives. The Cray Cave is a low arch on the eastern side that fills with bullseyes and squirrelfish in dense schools. A typical boat dive runs 45 to 60 minutes through multiple terrain transitions, with operators positioning each dive to match the day's current and the divers' certification.

The species that draws international divers to Byron is the leopard shark. From late November through May, these patterned, spotted sharks haul out on the sand patches and rubble at the base of the moorings, often in dozens at peak season, resting on the bottom and cruising with the slow tail-flick that betrays their nurse-shark lineage. As the leopards thin out in autumn, grey nurse sharks build through winter and into spring, holding in mid-water along the eastern walls and cycling through the gutters at low tide. Manta rays appear in waves between November and May, sometimes feeding head-on into the current at the surface, sometimes cruising past divers on the reef. The supporting cast is dense: green and loggerhead turtles year-round, banded and tasselled wobbegongs sleeping under ledges, eagle rays gliding across the sand, and large bull rays digging at the base of the bommies. Pelagics work the corners on tide change, with kingfish, longtail tuna and Spanish mackerel showing through summer. Black cod, critically endangered on the east coast, are resident in the deeper holes.

Visibility at Julian Rocks typically runs 10 to 25 metres, with the best clarity in late summer and autumn when the East Australian Current is established and the coastal rivers are running clean. Heavy rain in the Brunswick or Richmond catchments can drop visibility hard and fast, sometimes within twelve hours of the storm. Water temperature ranges from around 19°C in August to 26°C in February. A 5mm wetsuit handles the cooler months comfortably; a 3mm shortie is enough through summer. Currents at Julian's are tide-driven and can be strong, particularly on running tides at the eastern face and in Hugo's Trench, and operators time entries to slack water and brief drift protocols where applicable. Surface swell is the variable that closes the site: anything over two and a half metres typically makes the moorings unworkable, and easterly swells wrap into the western lee. Summer is peak for leopard sharks, mantas and warm-water clarity. Winter and early spring deliver the grey nurse aggregations and the humpback migration that often meets boats during the surface transit.

Beyond the headline animals, Julian's rewards repeat divers willing to slow down. The Cray Cave fills with bullseyes and squirrelfish in dense schools that part as divers ease through. Pygmy seahorses live on the gorgonians at the deeper end of Hugo's Trench and reward patient hunting at slack water. The walls of the Cod Hole hold nudibranchs through the cooler months and resident anglerfish that survey the swim-through from their perch points. Whale sharks are recorded once or twice a year on long-tide days through autumn, and dwarf minke whales have been encountered on transit during the southern migration. Photographers working the site over multiple days find the same boulder hosts a different cast each season, and even the mooring lines on safety stops reward a careful look for tropical juveniles riding south on the current.

Julian Rocks is the dive that demonstrates what the east coast's collision of currents actually means for the divers in the water. On any given day someone surfaces and tries to catalogue what they have just seen, the leopard shark resting metres from a grey nurse, the manta passing while turtles work the shallows, and finds that the list refuses the usual neat categories. The Bundjalung name remembers what divers learn quickly: this is a place older, fuller and more alive than its small footprint suggests.

## Site Access and Logistics

Julian Rocks is a boat dive only. Both operators depart Byron Bay's Main Beach via beach launch in rigid inflatable boats, with a transit of around 15 minutes to the moorings. The standard booking is a two-tank trip with a brief surface interval at the rocks or a return to the beach between dives.

Entry is a backward roll from the RIB onto the mooring line. Exit is a controlled ascent back up the line and a re-board over the boat tubes, with safety stops conducted on the line in any current. Operators issue surface marker buoys for the eastern and southern sub-sites where drift conditions are possible.

Minimum certification is PADI Open Water, with operators selecting sub-sites by certification and experience: sheltered, shallow sites such as The Nursery and Cod Hole for newer divers; Hugo's Trench and the eastern face for Advanced Open Water and above. Twenty logged dives is a sensible working minimum for the deeper sub-sites. Nitrox is available through both operators and is recommended for divers booking multiple dives across consecutive days.

Bookings, gear hire and accommodation packages run through [Sundive Byron Bay](https://www.sundive.com.au) and [Byron Bay Dive Centre](https://www.byronbaydivecentre.com.au), the two long-established operators servicing the site.

## Sources

- Sundive Byron Bay, dive site descriptions and seasonal briefings: [https://www.sundive.com.au](https://www.sundive.com.au) - Byron Bay Dive Centre, operator site notes: [https://www.byronbaydivecentre.com.au](https://www.byronbaydivecentre.com.au) - NSW Department of Planning and Environment, Cape Byron Marine Park zoning and management: [https://www.marine.nsw.gov.au](https://www.marine.nsw.gov.au) - Michael McFadyen's Scuba Diving, Julian Rocks reference: [http://www.michaelmcfadyenscuba.info](http://www.michaelmcfadyenscuba.info) - Australian Marine Conservation Society, leopard shark and grey nurse east coast distribution - PADI Travel, Julian Rocks site profile