Mudjimba Island (Old Woman Island)

Mudjimba Island (Old Woman Island) Dive Site Guide | Sunshine Coast, QLD, Australia

By ScubaDownUnder Team · 2026-02-01

Four kilometres off Maroochydore, a rocky outcrop breaks the line of an otherwise flat coast, small, unforgiving above the surface, and quietly thriving below it. The skipper drops the mooring on the eastern face, the water glows pale green over the reef ledges, and a green turtle rises briefly from a patch of algae to breathe before returning to its meal. Mudjimba Island (Old Woman Island) is not a dive that trades in drama. It trades in resident animals, healthy reef and the kind of forgiving depth that lets newer divers spend proper time underwater while experienced divers read the macro detail with unhurried attention.

The island sits within the Mudjimba Island Conservation Park, managed by Queensland Parks and Wildlife Service, and has never been permanently inhabited. It breaks the surface as a rocky remnant of older volcanic activity along the southeast Queensland coast, and its protection has allowed the marine ecosystem around it to develop with minimal direct human impact. The Kabi Kabi (Gubbi Gubbi) people are the recognised Traditional Custodians of the Sunshine Coast, and the island, known traditionally as Mudjimba, has long been part of their cultural seascape. Landing on the island itself is restricted to protect seabird nesting habitat, which keeps the visitor footprint entirely in the water.

The dive environment varies with conditions. The eastern and northeastern faces are the most commonly dived, offering a series of rocky bommies and reef ledges that descend from around 6 metres down to 18 metres before the reef transitions to sand. The structure is heavily encrusted with sponges, ascidians and hard corals, with pronounced gutters and overhangs that create shelter for the resident community. The substrate shifts between reef slabs, sand channels, and coarse rubble, and at the base of the deeper sections, the sandy floor hosts its own cast: bartail flatheads buried to their eyes, small rays gliding across the open, and occasional leopard sharks resting through the warmer months. Green turtles work the algae on the upper reef, often continuing to feed as a diver passes within arm's reach, and the absence of hurry in their movement sets the tone for the rest of the dive.

Green turtles are the site's most dependable residents, and encounters here tend to be close and unhurried. Loggerhead turtles appear less predictably but register with genuine impact when they do. Wobbegong sharks occupy the ledges and undercuts throughout the reef; their cryptic patterning makes them easy to miss on a first pass, and finding a large specimen tucked into a gutter is one of the small satisfactions of a second or third dive at the site. Cuttlefish in the shallower sections are notably curious and will often approach divers, cycling through colour patterns that suggest active assessment rather than alarm. Yellowtail scad, luderick and silver trevally orbit the bommies in tight formations, frequently shadowed by larger maori wrasse working the water column above. Humpback whales pass offshore between June and November, and their song can sometimes be heard through the water column during the migration months. Eagle rays and bull rays cross the sand flats below the reef, unhurried and deliberate.

Visibility typically ranges from 8 to 15 metres, with the best conditions arriving in late summer through autumn as the East Australian Current pushes cleaner water south along the coast and ocean swells settle. Winter brings cooler temperatures in the 19 to 21°C range and occasional reduction in visibility during south-easterly swell events, but the site continues to dive well into July and August. A 3mm wetsuit suits the warmer months; a 5mm is the better choice from June through September. Tidal currents around the northern and southern ends of the island can be pronounced on spring tides, and the dive is best timed to slack water or a neap cycle when water movement is minimal. The northwest face offers some shelter from south-easterly swell, and skippers choose the dive side based on conditions on the day. Summer brings occasional stinger activity and increased boat traffic; the site is at its most reliable between April and November.

Repeat divers look beyond the turtles. The sponge-encrusted gutters hold a surprising nudibranch community, particularly through the cooler months when metabolic rates slow and species that favour cooler water become more active. Small crabs inhabit the rubble zones, decorator crabs use the sponge faces as camouflage supply, and the shallow reef tops carry small reef fish populations that reward a torch and a slower pace. Night dives on the island produce a different reef entirely, the wobbegongs shift from ambush mode to active hunting, Spanish dancers emerge onto the open reef, and basket stars unfurl into the current. Operators often pair Mudjimba with the Ex-HMAS Brisbane wreck for a full day on the water; the shallow profile of the island suits a second dive after the wreck's deeper profile.

Mudjimba does not have the dramatic architecture of a deep wall or the population density of a cleaning station site, and it makes no attempt to be something it is not. What it offers, consistently, is a protected reef with animals that have grown used to considerate divers, and the kind of unhurried dive that rewards time in the water rather than distance covered.

## Site Access and Logistics

Mudjimba Island is boat-only, accessed from Mooloolaba Harbour with a transit of around 10 to 15 minutes. Public landing on the island is restricted under the conservation park management plan. Sunreef Mooloolaba (https://www.sunreef.com.au), located at Shop 11 to 12, The Wharf Mooloolaba, 123 Parkyn Parade, is the long-established PADI operator for the site and includes Mudjimba on regular day-trip itineraries, often paired with the Ex-HMAS Brisbane wreck. Scuba World, also based in Mooloolaba, runs trips to the site as well. Open Water certification is the minimum, and the site is well suited to recently certified divers building logged experience on live reef. Enriched air nitrox is available through local operators but not necessary at this depth. Metered parking is available on Parkyn Parade near the marina, with public toilets at the Mooloolaba Beach reserve. Full services, including food and accommodation, are available in Mooloolaba township.

## Sources

- Sunreef Mooloolaba, Mudjimba Island dive description (https://www.sunreef.com.au/dive-sunshine-coast/sunshine-coast-reef-dives/mudjimba-island/) - Visit Sunshine Coast, Mudjimba (Old Woman) Island dive site (https://www.visitsunshinecoast.com/attraction/56b265932880253d74c4dd60/mudjimba-old-woman-island-dive-site) - Queensland Parks and Wildlife Service, Mudjimba Island Conservation Park - Scuba World Mooloolaba (https://scubaworld.com.au) - Atlas of Living Australia, green turtle (Chelonia mydas) and wobbegong distribution records