Photo: Heidi Bruce / Unsplash
Ribbon Reefs & Cod Hole
The Ribbon Reefs are a chain of ten narrow offshore reefs on the outer edge of the northern Great Barrier Reef, off Queensland. They are reachable only by liveaboard from Cairns; some operators shorten the trip with a light-aircraft transfer to or from Lizard Island. The signature dive is the Cod Hole on Ribbon Reef 10, where potato cod reaching up to 2m and around 100kg approach divers, a behaviour reinforced by decades of feeding. The reefs are also known for isolated pinnacles, or bommies, that rise from about 30m to near the surface: Lighthouse Bommie, Steve's Bommie and Pixie Pinnacle among them, dense with schooling fish and soft coral. Each June and July, dwarf minke whales gather on the northern Ribbon Reefs, the only known predictable aggregation of this whale anywhere, and swimmers can encounter them under a licensed, research-linked code of practice. Most dives are moderate, but pinnacles and passes such as Dynamite Pass run current, so Advanced certification is the practical baseline. Trips run 3 to 7 nights and are not cheap. Coral condition is mixed: the northern offshore reefs came through the 2024 mass bleaching event better than the central and southern GBR, but the reef as a whole has bleached five times since 2016, so expect some damaged sections alongside healthy ones.
What makes it special
- The Cod Hole on Ribbon Reef 10: resident potato cod up to ~2m and ~100kg that approach divers
- Isolated bommies (Lighthouse, Steve's, Pixie) rising from ~30m to near the surface, dense with schooling fish and soft coral
- The June-July dwarf minke whale aggregation, the only known predictable gathering of the whale in the world, with licensed swim-with encounters
- A 30-year research partnership between operators and James Cook University's Minke Whale Project, with a researcher aboard every minke expedition
Price range
$$$
Trip length
3–7 days
Diver level
Advanced open water
Trip type
Liveaboard
Price is per person for a typical trip, excluding international flights ($$$ = over $4,000).
Liveaboard-only. Mike Ball's April 2026-March 2027 rates run from about AUD $2,500 (budget cabin, 3-night Fly Dive Cod Hole) to about AUD $7,000 (premium, 7-night Coral Sea Safari) per person, with 4-night and 5-night Cod Hole/Coral Sea trips in the AUD $2,800-$5,000 range depending on cabin. Add the government Environmental Management Charge of AUD $8.50 per day (capped at 3 days on multi-day trips), a fuel surcharge of about AUD $20 per person per night for departures from May 2026, and international/domestic flights to Cairns. Minke expeditions also suggest a voluntary AUD $15/day donation to the Minke Whale Project.
Best time to dive
- Current
- Moderate
- Water temp
- 22–30°C (coldest Jul, warmest Jan)
- Visibility
- 15–30m — Commonly 15-30m on the outer Ribbon Reefs, generally better in the drier winter months (June-October). Approximate; operators report site-to-site and tide-driven variation rather than published monthly figures.
- Getting there
- Moderate — Reachable but with some friction: a 10h boat crossing.
- Experience
- Sheltered reef sections suit Open Water divers, but the pinnacles (Lighthouse, Steve's, Pixie) and passes such as Dynamite Pass run current and reach 30m+, so Advanced Open Water is the practical baseline. Night dives and drift dives feature on most itineraries.
Nearest airports
- CNS — Cairns Airport (Main arrival airport; liveaboards board in Cairns, and most itineraries depart or return here)
- LZR — Lizard Island Airport (Used for fly-dive transfers by light aircraft (about 1 hour from Cairns) to shorten the crossing to the northern Ribbon Reefs)
Marine life
Sightings are never guaranteed — the bars show typical likelihood by month.
| Month | Likelihood |
|---|---|
| January | not seen |
| February | not seen |
| March | not seen |
| April | not seen |
| May | rare |
| June | peak season |
| July | peak season |
| August | rare |
| September | not seen |
| October | not seen |
| November | not seen |
| December | not seen |
Strongly seasonal: the aggregation forms on the northern Ribbon Reefs in June and July only, coinciding with the whales' winter migration. Roughly 60-80 whales are thought to congregate off the northern Ribbon Reefs in those months. Operators cite about a 98% seasonal success rate, but any single encounter is not guaranteed. Effectively absent the rest of the year.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident on the Ribbon Reefs (locally called Maori wrasse); commonly seen at the Cod Hole and along outer reef walls. Endangered globally, protected in the Marine Park. Not seasonal.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident year-round at the Cod Hole and reliably seen there; not migratory. Numbers on any given dive vary. Reused voice: sightings are close and frequent but not guaranteed.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Occasional at the Cod Hole and Lighthouse Bommie; reported at cleaning stations and in passing rather than reliably resident. No strong single-month peak documented for the Ribbon Reefs.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident; forms dense schools around the pinnacles, notably Steve's Bommie and Pixie Pinnacle. Year-round; not seasonal.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident and commonly seen in the passes and along outer reef walls, especially in current at sites like Dynamite Pass. Year-round; not seasonal.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident; a camouflaged bottom-dweller found on the pinnacles and coral heads, including Steve's Bommie. Year-round; sightings depend on spotting them against the reef.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident in the coral heads and ledges across the Ribbon Reefs; commonly seen at Challenger Bay and Two Towers, more active at night. Year-round.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident; schools of barracuda are a fixture at the bommies (Lighthouse, Steve's, Pixie). Seen year-round.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident year-round on the Ribbon Reefs; not seasonal. Commonly seen, particularly at exposed reef sites; encounters vary dive to dive.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident; most active as a hunter on night dives at sheltered sites such as Challenger Bay. Seen year-round, encounters vary.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident and commonly seen across the Ribbon Reefs year-round, including at Lighthouse Bommie, Dynamite Pass and Flare Point. Not seasonal.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident on the Ribbon Reefs, commonly seen resting under ledges by day; regular at drift and wall sites. Not seasonal.
Dive sites
Worth knowing before you book
- Liveaboard-only and expensive: figure roughly AUD $2,500-$7,000 per person plus flights, EMC and fuel surcharge, with no land-based or day-trip alternative to the Ribbon Reefs.
- The dwarf minke whale swim season is narrow, essentially June and July only; outside that window the whales are gone even though the reef diving continues year-round.
- Coral condition is uneven after five mass bleaching events since 2016, including the record-footprint 2024 event; the northern offshore reefs fared comparatively well, but expect damaged sections alongside healthy coral.
- Reaching the northern Ribbon Reefs means an overnight crossing (or a light-aircraft transfer via Lizard Island); the open water can be rough and cause seasickness.
- Wildlife is never guaranteed: minke encounters run high (operators cite a ~98% seasonal success rate) but any single dive can come up empty, and potato cod numbers at the Cod Hole vary.
Sources & last checked
Checked July 2026
This is a researched draft, not yet human-verified. The seasonality and logistics are drawn from the sources below — confirm specifics (permits, fees, closures) with an operator before you book.
- Ribbon Reefs dive sites — Spirit of Freedom
- Cairns Liveaboard Dive Trip Price List 2026/27 — Mike Ball Dive Expeditions
- Environmental Management Charge - what are the charges — GBRMPA
- Annual Summary Report of Coral Reef Condition 2024/25 — Australian Institute of Marine Science (AIMS)
- Best Time to Dive Cairns: Month-by-Month Great Barrier Reef Guide — Cairns Dive Adventures
- 3 Night Great Barrier Reef Liveaboard — Spirit of Freedom
- Cod Hole Diving Liveaboard Cairns - 3 Night Fly Dive Cod Hole — Mike Ball Dive Expeditions
Note on the data: Coordinates and bounding box are approximate reef-chain positions, not surveyed dive-site GPS. Prices are from Mike Ball's published 2026/27 rates; other operators (Spirit of Freedom, Divers Den, Pro Dive) differ. EMC rate confirmed at AUD $8.50/day via operator rate page; primary GBRMPA charge page timed out on fetch. Visibility figures are operator-reported ranges, not published monthly data. Water temperature: Coral Sea surface temperature peaks near 29-30C in the Dec-Feb austral summer and cools to a winter low around 22-24C in Jul-Aug; there is no significant thermocline, and the monthly bands are interpolated from published seasonal figures. Access: Usually done as a liveaboard from Cairns, steaming about 10 hours overnight (roughly 240km north) to reach the Ribbon Reefs and Cod Hole; shorter trips can substitute a low-level scenic flight to/from Lizard Island, and Lizard Island offers a land base, so it is not strictly liveaboard-only. Independently verified 2026-07-20 (confidence low). Seasonality correction spot-checked and confirmed by the founder 2026-07-20; raised low → medium.