Nine Mile Reef

Nine Mile Reef, Tweed Heads

By ScubaDownUnder Team · 2026-09-17

Nine Mile Reef lies off Tweed Heads, where New South Wales meets the Gold Coast, and on its day Divernet's Nigel Marsh rates it among the best dives in Australia. It is a shark dive above all: [grey nurse sharks](https://scubadownunder.com/blog/the-grey-nurse-shark-the-gentle-giant-of-australias-reefs) gather in its gutters through winter, sometimes by the dozen, leopard sharks rest on the sand in summer, and [wobbegongs](https://scubadownunder.com/blog/wobbegong-the-camouflaged-carpet-shark-of-australia) live on the reef all year. Turtles, rays, schools of pelagic fish and the occasional manta ray fill out the cast.

Despite the name, Kirra Dive, which runs trips there from Tweed Heads, puts the reef about 4.5 nautical miles off the Tweed River entrance. It is boat-only and exposed, and the current can be strong: Divernet reports it sometimes running at three knots, and says trips are often planned and then cancelled. Even on a calm day the current can rule out a dive, so this is a site for experienced divers and settled weather.

## The Reef

Divernet describes Nine Mile Reef as a large ridge of rock with ledges, gutters and bommies. The top sits at about 8 to 12 m and the bottom reaches about 30 m: Divernet gives 12 to 30 m, Kirra 7 to 30 m, and Experience Gold Coast a reef top of about 10 m dropping to 30 m along a drop-off covered in hard and soft corals. Divernet adds black coral trees, gorgonians, sponges and ascidians. The gutters are where the grey nurse sharks gather, including the one known as the shark pit, and Kirra rates the South Wall one of the best wall dives in the area.

Because the current is usually running, most dives are drifts. Gold Coast Dive Adventures conducts it as a drift dive in most instances and finds the current strongest in summer. Kirra's plan for its deep drift dives is to drop in beside the wall, get down to its base out of the current, follow the wall past a long sand patch where sharks and big groper sit, and finish with a safety stop on a surface marker buoy before pick-up.

## Sharks Through the Seasons

The grey nurse sharks arrive in winter and gather in the shark pit. Divernet says numbers range from a few to several dozen, and that on one dive a few years ago its team counted more than a hundred; Kirra says there are usually twenty or more in the gutters during the winter months. As the water warms the grey nurse sharks leave and leopard sharks move in. The leopard sharks feed at night and rest on the bottom by day, docile and easy to approach for photographs. Kirra's South Wall is the place for leopard sharks and eagle rays in the warmer months.

Wobbegongs are resident all year, three species of them according to Divernet, and bull sharks, bronze whalers and the occasional hammerhead drop in from time to time (Experience Gold Coast). Divernet notes that the first divers here in the 1960s saw bronze whalers and makos regularly, especially when spearfishing, and the odd bronze whaler still turns up. Also on the list are stingrays, wedgefish, eagle rays, schools of cownose rays, bamboo sharks, turtles, schools of pelagic fish, giant Queensland groper and the occasional manta ray.

## Conditions

Visibility on the reefs off Tweed Heads is generally around 12 m, and Nine Mile Reef usually has the clearest water of them; Divernet says visibility is best after a week or so of southerly winds. No operator publishes a water temperature for Nine Mile Reef itself. For nearby Cook Island, Kirra gives about 19°C in winter to about 26°C at the height of summer.

Grey nurse sharks are listed as critically endangered in NSW, and NSW DPIRD applies the national code of conduct for diving with them in all NSW waters. It is the standard to follow on any grey nurse dive: do not touch, feed, chase or harass the sharks, do not block gutters or cave entrances, do not use mechanical devices such as scooters or shark pods, and keep groups to ten divers or fewer. Gold Coast Dive Adventures also invites divers to send side-on ID photos to Grey Nurse Shark Watch, a Reef Check Australia monitoring program.

## Site Access and Logistics

Nine Mile Reef is a boat dive only. Kirra Dive runs it from Tweed Heads as an advanced double dive: about 10 minutes along the Tweed River, a light bar crossing, then about 20 minutes to the site. If it cannot get out to Nine Mile, its next-best deep dive is Mary's Rock at [Cook Island](https://scubadownunder.com/blog/cook-island-a-sanctuary-of-turtles-and-vibrant-reefs). Gold Coast Dive Adventures runs two- and three-dive Nine Mile trips from Runaway Bay Marina between June and November, with around 55 minutes on the boat to reach the reef. It spends the surface interval in the shelter of Cook Island, and its three-dive trips may finish on the [Scottish Prince wreck](https://scubadownunder.com/blog/scottish-prince-shipwreck).

This is an advanced site. At the time of writing, Gold Coast Dive Adventures asks for Advanced certification (30 m), at least 30 logged dives and a dive in the last 12 months, and Kirra asks for Advanced certification and a dive in the last six months. Carry a surface marker buoy and be confident with buoyancy control in current. When conditions rule Nine Mile out, both operators go to backup sites, so treat the reef as a target for the day rather than a promise.

## Sources

- [Divernet: A Guide to Diving the Gold Coast, Part 2: Cook Island, Nine Mile Reef and Beyond](https://divernet.com/world-dives/australia-oceania/diving-the-gold-coast-cook-island-nine-mile-reef/) - [Kirra Dive: Advanced location SCUBA](https://kirradive.com/charters/advanced-double-scuba-dive-certified-m-149-) - [Kirra Dive: Double Dive Cook Island](https://kirradive.com/charters/cook-double-scuba-dive-certified-m-139-) - [Gold Coast Dive Adventures: Nine Mile Reef dive trip](https://goldcoastdiveadventures.com.au/nine-mile-reef-dive-trip/) - [Experience Gold Coast: Nine Mile Reef Dive Site](https://experiencegoldcoast.com/places-to-go/southern-gold-coast/things-to-do/nine-mile-reef-dive-site-au0062419) - NSW DPIRD: Greynurse shark (dpird.nsw.gov.au) - NSW DPIRD: Fishing and diving rules at Greynurse Shark aggregation sites (dpird.nsw.gov.au)

Header photo: a grey nurse shark near South West Rocks, New South Wales (not at Nine Mile Reef), by Christopher Mark, [CC BY 4.0, via Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Carcharias_taurus_12616854.jpg).