Turtle Caves is the fourth of Flat Rock's named dive sites, and as the name suggests it is where turtles are most reliably found resting under ledges and in the mouths of the caves. Sources give different depth ranges – marinelife.org.au lists 5-16 m for the site's coral gardens, while Gold Coast Dive Adventures describes it as 12-30 m, with shallower sections suitable for beginners and currents in the deeper areas – which reflects a site that runs from shallow coral down a reef slope. The caves are the feature.

Undercuts and small caverns in the rock provide resting places for green and loggerhead turtles, and divers who approach slowly can watch them at close range. Around the caves, bull rays and pygmy devil (mobula) rays are recorded, wobbegongs rest on the sand, and in winter grey nurse sharks move through Flat Rock's deeper gutters. The shallower coral gardens hold tropical fish, octopus, moray eels and nudibranchs, and leopard sharks visit between November and April.

Australia Dive describes Turtle Caves as the deeper Flat Rock site for bull rays, pygmy mantas and wobbegongs. As with all Flat Rock sites, the protected no-take status keeps fish numbers high and animals relaxed. The caves are not a penetration dive; divers look in from the entrance and should not crowd resting turtles or block their exit, as turtles need to surface to breathe.

Turtle Caves suits a broad range of divers and is often chosen as an alternative to The Nursery when a little more depth and structure is wanted.

Drive to Cleveland (about 40 minutes from Brisbane) and take the SeaLink vehicle ferry or a passenger water taxi across to Dunwich on North Stradbroke Island, then drive about 20 km (25 minutes) east to Point Lookout. Manta Lodge & Scuba Centre at Point Lookout runs the dives, beach-launching its boats and reaching the Point Lookout sites in roughly 5-15 minutes. Brisbane operators (Brisbane Scuba from Manly, Gold Coast Dive Adventures from Runaway Bay) also run occasional day trips.

Turtle Caves is one of the four Flat Rock sites, 10-15 minutes from Point Lookout.

Flat Rock is exposed to the open ocean. South-easterly winds over about 15-20 knots and easterly swell over about 1.5-2 m make the moorings rough and create surge; summer northerlies also chop up the site. Visibility ranges from 10 to 30 m, best in winter, and drops to a few metres after summer storms and heavy rain.

Morning dives are usually calmer before the afternoon sea breeze. Shallower sections suit beginners, but the deeper areas can carry current.

Descend to the reef, visit the caves at mid-depth looking for resting turtles without disturbing them, then explore the ledges and sand edges for rays and wobbegongs before returning up the reef to the mooring.

Manta Lodge & Scuba Centre – regular Flat Rock dives; Gold Coast Dive Adventures – Straddie trips.