Osprey Reef & Coral Sea

Osprey Reef is an isolated seamount more than 300km from Cairns, reached only on expedition liveaboards. Walls around North Horn, Admiralty and False Entrance descend toward 1,000m.

Best time
Aug–Nov
Certification
Advanced open water
Budget
$$–$$$ · $2,000–4,000 to over $4,000
Trip length
4–8 days
Trip style
Liveaboard
Access
Demanding

The short version

Known forIsolated Coral Sea seamount more than 300km offshore.

Main tradeoffLiveaboard-only access makes the trip expensive and impossible to reschedule casually.

Osprey Reef & Coral Sea dive region

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Your outlook

Explore 4 dive sites

Browse the map and wildlife below, or add an optional preference to narrow Osprey Reef & Coral Sea.

Most relevant wildlife

  • Potato codApr–Dec
  • Reef manta rayApr–Dec
  • Tiger sharkApr–Dec
  • Grey reef sharkApr–Dec

Plan the trip

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4 sites shown.

Conditions referenceSeason, water and visibilityBest Aug–Nov · Strong current · 23–30°C (coldest Jul, warmest Jan)
Best months Operating Closed / no trips
Current
Strong
Water temperature
23–30°C (coldest Jul, warmest Jan)
Visibility
20–40m: Operator-reported oceanic range, not a guaranteed monthly measurement.
Experience
Advanced certification and recent experience are prudent.

01 · Marine life

What you may see

rareoccasionalcommonly seenpeak seasondestination closed

Sightings are never guaranteed. The bars show typical likelihood by month.

Potato codEpinephelus tukula
Sighting likelihood by month
MonthLikelihood
Januarydestination closed
Februarydestination closed
Marchdestination closed
Apriloccasional
Mayoccasional
Juneoccasional
Julyoccasional
Augustoccasional
Septemberoccasional
Octoberoccasional
Novemberoccasional
Decemberoccasional

Possible throughout the operating year; no unsupported monthly peak is applied.

Reef manta rayMobula alfredi
Sighting likelihood by month
MonthLikelihood
Januarydestination closed
Februarydestination closed
Marchdestination closed
Apriloccasional
Mayoccasional
Juneoccasional
Julyoccasional
Augustoccasional
Septemberoccasional
Octoberoccasional
Novemberoccasional
Decemberoccasional

Possible throughout the operating year; no unsupported monthly peak is applied.

Tiger sharkGaleocerdo cuvier
Sighting likelihood by month
MonthLikelihood
Januarydestination closed
Februarydestination closed
Marchdestination closed
Apriloccasional
Mayoccasional
Juneoccasional
Julyoccasional
Augustoccasional
Septemberoccasional
Octoberoccasional
Novemberoccasional
Decemberoccasional

Possible throughout the operating year; no unsupported monthly peak is applied.

Grey reef sharkCarcharhinus amblyrhynchos
Sighting likelihood by month
MonthLikelihood
Januarydestination closed
Februarydestination closed
Marchdestination closed
Apriloccasional
Mayoccasional
Juneoccasional
Julyoccasional
Augustoccasional
Septemberoccasional
Octoberoccasional
Novemberoccasional
Decemberoccasional

Possible throughout the operating year; no unsupported monthly peak is applied.

See all 8 species

02 · Dive sites

Dive sites worth knowing

A starting point, not a ranking. Conditions decide what works on the day.

See all 4 dive sites
03 · LogisticsGetting there and costsDemanding. Fly to CNS. Typical trip $$–$$$.

Route overview

Demanding

Liveaboard only, with a 12h open-ocean crossing to reach the diving.

Airport options

CNS

Cairns Airport

Short road transfer to Cairns liveaboard wharf

Typical trip cost

$$–$$$

$2,000–4,000 to over $4,000

Per person, excluding international flights.

  • Four-night Coral Sea expeditions commonly cost several thousand AUD; seven-night itineraries and premium cabins can exceed USD 4,000 equivalent before flights and extras.

Sources & last checked

Checked September 2026

Research is source-backed, but conditions and fees should still be confirmed locally.

View 4 sources and checking notes

Note on the data: Operator route names and schedules change. Site coordinates are approximate. Shark abundance at North Horn is partly influenced by deliberate attraction. No personal permit is inferred from operator authorisation. Water temperature: Rounded regional surface-water bands; exposed Coral Sea dive depth can feel cooler. Access: Trips embark in Cairns and travel overnight or combine a Cairns departure with a Lizard Island flight. Twelve hours is a planning estimate, not a fixed crossing time.