Marine life
Potato Cod
Epinephelus tukula
Enormous, docile groupers habituated to divers at Cod Hole on the Ribbon Reefs.
Cod Hole on the northern Ribbon Reefs is one of the oldest and most famous dive sites in Australia, and the potato cod are the reason. These are enormous fish — well over a metre and a half, with the bulk of a small car bonnet — that have been habituated to divers since the 1970s.
They approach closely and hold station beside divers, which produces the scale-defying photographs the site is known for. It is one of very few places where a diver reliably shares the water with a fish that large and that unbothered.
The site is reached by liveaboard from Cairns or Port Douglas, and is usually combined with the Ribbon Reefs and Coral Sea on a multi-day itinerary.
| Scientific name | Epinephelus tukula |
|---|---|
| Typical size | Commonly 1.5–2 m |
| Peak months | June, July |
| Documented sites | 2 |
| States | Queensland |
- massive, heavy-bodied grouper
- pale grey to fawn with large dark blotches
- prominent thick lips and a very wide mouth
- moves slowly and deliberately
- Habituated to divers at Cod Hole through decades of interaction.
- Ambush predator on fish and crustaceans.
- Highly site-faithful — the same individuals are recognised over many years.
In-water etiquette
How divers behave around this species affects both the animal and everyone else's encounter.
- Do not feed — feeding has been curtailed and changes behaviour.
- Do not touch or attempt to ride, however tolerant an individual appears.
- Keep hands in and be aware of your surroundings; these are very large fish moving close.
Where to see them
Sites where this species is documented as a reliable encounter.
Operators servicing those sites
Businesses documented as diving the sites above. Confirm seasonality and requirements directly.
Often seen on the same dives
Frequently asked questions
Where can I dive with potato cod?
Cod Hole on the northern Ribbon Reefs, reached by liveaboard from Cairns or Port Douglas.
Last researched: September 2026. Dive businesses change frequently — confirm current services, prices and requirements directly with the operator before booking.