Julian Rocks (Nguthungulli)

Moderate risk: Strong currents at depth

Currents can be strong around the rock outcrops and deeper dive sites like Hugo's Trench and The Cod Hole. Snorkellers should stay in the shallower western side.

Moderate risk: Ocean swell surge

Ocean swell can create surge inside the trench, reducing visibility and making it harder to navigate the narrow rock passages.

Moderate risk: Ocean current around bommies

Current can run strongly around the bommies and rock formations; operators assess conditions daily and select sites accordingly.

Moderate risk: Strong ocean currents

The East Australian Current can create swift tidal flows around the rock formation, requiring reasonable swimming fitness.

Moderate risk: Open ocean exposure

Located 2.5 km offshore with no sheltered beach access; conditions can change rapidly with wind and swell.

Moderate risk: Strong tidal currents

The convergence of currents around the rocks can create powerful surges, especially around Hugo's Trench and The Needles. Snorkelers should be confident swimmers.

Moderate risk: Swell and surf exposure

Exposed to open ocean swells, conditions can change rapidly with increased wind. The south-eastern side gets rougher in southerly swells.

Moderate risk: Strong currents at tide changes

The convergence of warm and cool currents around Julian Rocks can create unpredictable surge and sweeping currents, especially near the rock edges during outgoing tide.

Moderate risk: Tidal current

Moderate currents can sweep through the trench, particularly on changing tides. Best visited on slack tide.

Moderate risk: Swell and surge

Being an offshore oceanic site exposed to the Pacific, conditions can change rapidly. Swell can create surge through the trench passages, requiring careful navigation.

Moderate risk: Ocean current

Current can run strongly around the bommies depending on tide and weather. Site selection made on the day by operators based on conditions.

Moderate risk: Depth

The Cod Hole swim-through ranges from 15 to 20 metres — suitable for experienced snorkellers with good breath-hold or certified divers.

Low risk: Boat traffic

Julian Rocks is accessed by tour boats. Snorkellers share the area with dive boats — stay aware of vessel movements.

Low risk: Marine stingers

Bluebottles and jellyfish may be present, particularly in warmer months (November to March).

Low risk: Grey nurse shark presence

Julian Rocks is a critical grey nurse shark habitat. These protected sharks are generally docile but should be observed with respect and not approached closely.

Low risk: Outgoing tide current

A surface current can develop around the rocks on an outgoing tide, especially near the south-eastern side. Snorkellers should stay close to the boat or guide.

Low risk: Humpback whale migration

May to September is the annual humpback whale migration corridor between the rocks and mainland. Maintain safe distances from whales.

Low risk: Shallow reef bommies

Shallow reef shelves (5-12 m) at The Nursery have rocky outcrops and bommies that can cause scrapes. Wear a full wetsuit or rash guard.

Low risk: Strong Currents

The East Australian Current can create strong, unpredictable flows around the rocks, particularly on the outer edges. Best to stay with a guide.

Low risk: Sharp Reef

Shallow reef areas have sharp coral and rock formations. Snorkelers should wear fins and avoid standing on the reef.

Low risk: Cold water upwelling

Southern ocean swells can bring cooler water and reduced visibility, particularly in winter months.

Low risk: Rough sea conditions (boat transit)

When the swell picks up, the boat ride out and back from Byron Bay can be very rough. Not recommended for those prone to seasickness.

Low risk: Variable visibility

Visibility ranges 10–20 m but can drop during plankton blooms (summer) or after heavy rain.

Low risk: Cold water temperature (winter)

Water temperature from 18°C (winter) to 27°C (summer); cold shock/increased exertion risk in winter without appropriate wetsuit.

Low risk: Strong currents at convergence zone

Tropical and temperate currents meet here, creating unpredictable water movement around the rocks.

Low risk: Limited visibility after weather

Visibility can drop significantly after storms or strong swell, making navigation challenging.

Low risk: Depth variation

Drop-offs from shallow nursery areas (5 m) to deeper swim-throughs (18-25 m) can surprise inexperienced snorkelers staying near the rocks.

Low risk: Cold Water Thermoclines

Seasonal upwelling can cause sudden temperature drops of several degrees, especially in deeper sections like Cod Hole.

Low risk: Sharp Reef & Rock Outcrops

Exposed rock pinnacles and shallow reef ledges at The Nursery and Cod Hole can cause cuts and scrapes.

Low risk: Ocean currents

Tidal currents can run through the trench creating sudden changes in water movement, particularly around the narrow canyon sections.

Low risk: Sharp volcanic rock

The volcanic rock formations have sharp edges; care needed when entering/exiting the water or swimming near walls.

Low risk: Swell Exposure

The pinnacles are exposed to open ocean swell. Conditions can change quickly, reducing visibility or creating surge around the rocks. Best in calm conditions.

Low risk: Wobbegong sharks

Tasselled wobbegong sharks rest camouflaged on the rocky ledges. They are not aggressive but can bite if stepped on or provoked. Snorkellers should keep a respectful distance.

Low risk: Cool Winter Water

Water temperature drops to around 18°C in winter (June–August), requiring a wetsuit for comfort.

Low risk: Shark presence

Grey nurse sharks (endangered but generally docile) and wobbegong sharks are common. Keep respectful distance and do not touch.

Low risk: Cold water temperatures

Waters can be cooler than expected, especially in winter (May–Sep). 5 mm wetsuit recommended.

Low risk: Depth changes

Depth varies from 5m at the shallowest points to 17-22m in and around the trench. Snorkelers should stay aware of their position relative to the reef.

Low risk: River outflow reducing visibility

Runoff from the Tweed, Brunswick, and Richmond Rivers can significantly reduce underwater visibility after heavy rain, particularly during the wet season (Nov–Mar).

Low risk: Grey Nurse Sharks (winter)

Grey nurse sharks aggregate around The Cod Hole during the cooler months (May to November). These are generally docile but should be treated with respect.