Flat Rock

Flat Rock, North Stradbroke Island

By ScubaDownUnder Team · 2026-04-14

Flat Rock is a wave-washed rock off Point Lookout on North Stradbroke Island (Minjerribah), dived above all for the grey nurse sharks that gather there each winter. The Queensland Government describes it as one of the most popular dive sites in [Queensland](https://scubadownunder.com/blog/best-places-to-dive-in-queensland) and one of the four known areas where grey nurse sharks congregate. Visit Brisbane places it a couple of kilometres north of the island, and Manta Lodge, the Point Lookout dive centre, calls it several kilometres offshore.

Despite the "submerged platform" label it is sometimes given, the rock breaks the surface. The Queensland Government's public mooring map shows it above water as a small island fringed by white water, and its Flat Rock research page is illustrated with waves washing onto it. UniDive's 2014 habitat map marks a large area of exposed rock in the middle, ringed by rocky reef with gullies, walls and ridges that slopes away through the 5, 10 and 20 m contours, with the map's deepest contours at 30 and 35 m.

## The dives around the rock

Flat Rock is several dives rather than one, and where you go depends on the day's wind and swell. Manta Lodge lists Turtle Cave, on the north-west side, at 10 to 30 m and rates it ADV on its scale, meaning less than 30 m, some current and variable surface conditions. It describes large schools of batfish, barracuda, turtles and several species of pelagic shark there, with eagle rays, grey nurse sharks and humpback whales in winter, and says a lone whale shark has dropped in for a day or two between February and April in recent years.

Shark Alley, on the opposite side of the rock from Turtle Cave, runs from 18 to 26 m and is also rated ADV. This is the winter grey nurse dive: Manta Lodge says large numbers of sharks sit on the sand channel between the two large sections of reef, with the odd bull shark or sandbar whaler and humpback whales in the area. UniDive's map labels the gutters on the eastern side of the rock the Shark Gutters.

When westerly wind or swell hits the rest of the rock, Manta Lodge heads to Big Bay on the northern, ocean side, at 8 to 18 m and rated from snorkel and Open Water up to ADV. UniDive's map also marks a Nursery on the western side, and Manta Lodge lists a shallow site called The Nursery, 4 to 18 m, for days of strong northerly wind.

Experienced divers have harder options close by. Roaring Deep is a 20 to 34 m drift that starts at the Turtle Cave mooring, runs around the ocean side of the rock and finishes at the Shark Alley mooring or with a blue-water ascent. Blue Corner is a deep reef a short swim north of the Shark Alley mooring, with its top at about 28 m and sand at 40 to 45 m. Manta Lodge rates both Master Diver or XR, its grades for deep, current-prone dives with live drops and pick-ups.

## Grey nurse sharks and other life

Grey nurse sharks are the reason most people come. The Queensland Government calls the species critically endangered and says the Australian east coast population is thought to contain no more than 2000 sharks. Manta Lodge and Visit Brisbane both point to winter as the time to see them at Shark Alley. Flat Rock is one of three grey nurse shark areas in Moreton Bay Marine Park, with Cherubs Cave and Henderson Rock off Moreton Island. Our [grey nurse shark guide](https://scubadownunder.com/blog/the-grey-nurse-shark-the-gentle-giant-of-australias-reefs) covers the species in more detail.

Visit Brisbane adds turtles, wobbegongs, leopard sharks, eagle rays, reef and pelagic fish and the odd manta ray to the list for Flat Rock. Mantas are far more reliable at nearby [Manta Bommie](https://scubadownunder.com/blog/manta-bommie), which Manta Lodge says comes alive with them from October to April; see also our guide to [manta rays in Australia](https://scubadownunder.com/blog/diving-with-manta-rays-in-australia).

UniDive's 2014 survey gives a measured picture of the reef itself. Macroalgae and turf algae covered more of the bottom than anything else at every site it surveyed off Point Lookout, but its Flat Rock East transect had the highest coral cover of the five, averaging 22.8 percent, mostly encrusting and branching hard corals. The survey recorded the most physical coral damage at Flat Rock West and Shag Rock East, and found fishing line at both Flat Rock transects despite the green zone. Across its 2001 and 2014 studies, UniDive recorded 316 fish species and 43 hard coral species on the Point Lookout reefs.

## The rules at Flat Rock

Flat Rock sits inside three overlapping designations in the Marine Parks (Moreton Bay) Zoning Plan 2019, each a circle of 1.2 km radius centred on 27°23.410'S, 153°33.070'E: a marine national park (green) zone, MNP19, where fishing and collecting are not allowed; a grey nurse shark area, GNS03; and a no-anchoring area, NAA02. UniDive notes that the green zone dates from the 2009 rezoning of the marine park.

Diving is allowed, but inside the grey nurse shark area the zoning plan says:

- No diving between 6 pm and 6 am unless you have a reasonable excuse. - Do not touch, feed, trap or try to trap a grey nurse shark, do not block a cave entrance or gutter, and do not interfere with a shark's natural behaviour, for example by chasing it or interrupting its swimming pattern. - No electro-acoustic or mechanical apparatus in the water, which the plan says includes scooters, horns and shark-repelling devices. Ordinary scuba equipment is exempt. - Outside a commercial tour, a group may have no more than 10 divers in the water at once. A tourism operator may have up to 12 in the water, but everyone beyond 10 must be a dive instructor or certified assistant, and operators and dive clubs must brief divers on the rules and display a sign stating them.

The plan also lets the Queensland Government close all or part of the area at short notice with a prohibited area notice, for example when a female shark has recently given birth or is about to, so check for current notices before you go.

Anchoring is banned throughout the 1.2 km circle. The Queensland Government's mooring map shows four public moorings at the rock: one class A mooring (vessels up to 10 m monohull or 9 m multihull) off the south-west side, and three class C moorings (up to 25 m monohull or 22 m multihull), one off the north-west side and two off the south-east. Each public mooring's tag shows its time limit, which may be two, four or 24 hours. UniDive says the moorings were installed in 2012.

The Queensland Parks and Wildlife Service has been studying how divers affect the sharks here, with field work at Flat Rock starting in March 2018. Some divers have reported fewer sharks than usual in the main gutter during the peak aggregation period and suggested the sharks are being disturbed by large numbers of divers, divers being present all day, or particular diver behaviour. The agency says this has not been scientifically confirmed and that the project report will be published once it has been peer reviewed. Keeping out of the gutter entrances and keeping groups small are rules here, not just good manners.

## Conditions

Manta Lodge's conditions page puts average visibility around North Stradbroke Island at 12 to 16 m, with 5 to 11 m typical in summer, and 17 to 24 m, sometimes more than 25 m, common in winter. It says excellent visibility is more common out at Turtle Cave because of the prevailing currents. Its monthly average water temperatures run from 19 to 20°C in July and August up to 25 to 26°C from January to March.

This is an exposed site. Manta Lodge warns that the area is prone to swell, current and wind with no outer reef to shelter behind, and that its small 6 m boats enter and leave through a surf beach. It also says it cannot guarantee any particular dive site, because every trip depends on conditions, diver experience and minimum numbers.

## Who it suits

Visit Brisbane lists depths of up to 35 m and says Flat Rock is for divers with Advanced Open Water qualifications. Manta Lodge rates Turtle Cave and Shark Alley ADV and Big Bay suitable from Open Water level. All of its dive trips require Open Water certification with proof, and a refresher if you have not dived in the past 12 months.

## Site Access and Logistics

Flat Rock is a boat dive. Manta Lodge & Scuba Centre, at 132 Dickson Way, Point Lookout, describes itself as the only full-service scuba diving centre on North Stradbroke Island. It runs double-dive trips from Friday to Tuesday and does not dive on Wednesdays. Morning trips meet at 6:45 am and return at about 11 am, afternoon trips meet at 11:45 am and return at about 4 pm, and its sites are a 10 to 15 minute ride from its beachside launch site. Hire equipment and nitrox are available. The Queensland Government says three commercial operators frequent Flat Rock, with other operators using it during the peak grey nurse shark season, and that dive clubs and private boats also visit.

North Stradbroke Island is reached only by passenger or vehicle ferry from Cleveland. Manta Lodge works with the Gold Cats Stradbroke Flyer from Toondah Harbour, at the end of Middle Street in Cleveland, to Dunwich, where its staff collect divers who have booked the Flyer through it; the 5:45 am Flyer connects with the morning trip. It does not arrange pickups from the water taxi or vehicle ferry.

If you come by private boat, pick up a public mooring of the right class rather than anchoring, observe the time limit on its tag, and stay out of the water from 6 pm to 6 am inside the grey nurse shark area.

## Sources

- [Manta Lodge & Scuba Centre: Dive Sites](https://www.mantalodge.com.au/dive-sites/) - [Manta Lodge & Scuba Centre: Dive Conditions](https://www.mantalodge.com.au/dive-conditions/) - [Manta Lodge & Scuba Centre: Scuba Diving](https://www.mantalodge.com.au/scuba-diving/) - [Manta Lodge & Scuba Centre: Snorkel Trips](https://www.mantalodge.com.au/snorkel-trips/) - [Manta Lodge & Scuba Centre: Getting to Straddie](https://www.mantalodge.com.au/day-trip-getting-to-straddie/) - [Queensland Legislation: Marine Parks (Moreton Bay) Zoning Plan 2019](https://www.legislation.qld.gov.au/view/html/inforce/current/sl-2019-0175) - Queensland Parks and Wildlife Service: Moreton Bay Marine Park provisions tables (parks.qld.gov.au/parks/moreton-bay/zoning/provisions-tables, not linked because it blocks automated checks) - [Queensland Government: Flat Rock public mooring map (PDF)](https://www.qld.gov.au/__data/assets/pdf_file/0035/99269/map-reef-public-moorings-moreton-bay-mp-flat-rock-nth-stradbroke.pdf) - [Queensland Government: Public moorings and no anchoring areas](https://www.qld.gov.au/environment/coasts-waterways/marine-parks/public-moorings-reef-protection-areas) - [Queensland Government: Flat Rock research project](https://www.qld.gov.au/environment/coasts-waterways/marine-parks/projects/flat-rock) - [Queensland Government: Grey nurse shark-diver interaction research project](https://www.qld.gov.au/environment/coasts-waterways/marine-parks/projects/grey-nurse-shark) - [UniDive (Roelfsema et al. 2014): Point Lookout Ecological Assessment (PLEA) Final Report](https://epic.awi.de/id/eprint/37389/1/Unidive_PLEA_2014_Final_Report.pdf) - [Visit Brisbane: Flat Rock Dive Site](https://visit.brisbane.qld.au/things-to-do/north-stradbroke-island/natural-attractions/flat-rock-dive-site-dd90) - [Wikipedia: North Stradbroke Island](https://en.wikipedia.org/wiki/North_Stradbroke_Island)

Header photo: A painted spiny lobster (Panulirus versicolor) in a reef crevice, geotagged at Flat Rock in June 2022, by Jean-Paul Boerekamps, [CC0, via Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Panulirus_versicolor_211184285.jpg).