North Horn, Osprey Reef

Verified2026-09-11 checkedWallPelagic

A seamount rising 1,000 m from the Coral Sea floor, with visibility that regularly passes 40 m.

Depth: 10–40 m33–131 ft
Difficulty: Advanced
Entry: Liveaboard
Typical current: Moderate
Coordinates: 13°54.000′S 146°33.000′E
Activities: Scuba

Osprey Reef is an isolated atoll well outside the Great Barrier Reef, reachable only by liveaboard. North Horn is its northern point, where the wall drops into very deep water and grey reef and whitetip sharks patrol an amphitheatre of ledges. Water clarity here is the best in Australian diving. Some operators run a shark feed at the site; whether to dive it is a judgement worth making before boarding rather than on the deck.

Liveaboard from Cairns or Port Douglas; around 12 hours of open crossing.

Best season

ExcellentJun–Oct
GoodMar–May
GoodNov–Dec

Before you get in

Past 30 m, where no-stop time and gas both go quickly and nitrogen narcosis starts to show.
A wall. There is no bottom in sight to judge against, so depth is kept by the gauge alone — and it is easy to end up deeper than intended.

Taken from this site’s recorded depth, type and current, and nothing else. An empty list is not a safe site — the sea on the day, the local geography and the boat traffic are not in it. The briefing on the spot comes first.

Conditions

Water temperature: 25.1°C77°F
Wave height: 1 m3 ft
Air temperature: 24.5°C76°F
Wind speed: 23.5 km/h14.6 mph

Updated 2026-10-07 16:15 UTC · Source: Open-Meteo

Weather data by Open-Meteo.com (CC BY 4.0)

Conditions are reported for information only. Assess the site yourself and follow your guide and your training.

No live conditions for this site yet.

We only show numbers we can attribute to a source.

Sea state and tide

On a date

Tide · 10/8

Low00:51-0.22 m
High06:421.27 m
Low12:37-0.25 m
High18:561.68 m

Forecast heights against mean sea level. Real tides in a bay, a harbour or over a flat can differ — check an official tide table before you get in.

Pick a day to see its tide

Only wave height and wind are scored, because those are what close a boat ramp or a shore entry. Water temperature is reported and never scored: 12°C is an ordinary dive in a drysuit and punishing in a 3 mm, and a number that cannot see your suit has no business marking it down. Stars do not decide whether you get in — you and your guide do, on the day.

Weather data by Open-Meteo.com (CC BY 4.0)

Marine life you may see

Grey reef sharkCarcharhinus amblyrhynchosCommon
Whitetip reef sharkTriaenodon obesusCommon
Potato codEpinephelus tukulaSeasonal
Giant trevallyCaranx ignobilisCommon
Staghorn coralAcropora spp.Common
Dwarf minke whaleBalaenoptera acutorostrataJun–JulSeasonal
Titan triggerfishBalistoides viridescensCommon
Moorish idolZanclus cornutusCommon
Feather starCrinoideaCommon

From divers

What people who were in the water reported. Not a forecast, and not a judgement about whether the site is safe to dive.

No recent reports from divers. If you dived here in the last two weeks, you can say how it was.

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