Great Barrier Reef North

The northern Great Barrier Reef is dived from Cairns and Port Douglas. Day boats reach outer reefs such as Norman, Saxon and Agincourt, while liveaboards work north along the Ribbon Reefs, a string of ten reefs about 120 km long ending east of Lizard Island, to the Cod Hole with its potato cod. Some liveaboard trips cross open ocean to Osprey Reef in the Coral Sea, a remote atoll with walls dropping over 400 m and many sharks. The Great Barrier Reef is a marine park managed by GBRMPA with Green no-take zones; Osprey Reef lies in the Australian Marine Parks' Coral Sea Marine Park.

Facts

• Best season: May to October is drier and the clearest, June to September often best; December to March is the wet season. Dwarf minke whales visit the Ribbon Reefs around June-July.
• Water temperature: About 22-24 C in winter (June-August) up to about 28-29 C in summer (December-March).
• Getting there: Fly to Cairns; day boats leave Cairns and Port Douglas, liveaboards from Cairns. The Cod Hole and Osprey Reef are practical only by liveaboard.
• Marine park rules: Great Barrier Reef Marine Park: diving is allowed in Green (no-take) zones, fishing and collecting are not; operators hold the permits and the environmental management charge is paid via the operator. Osprey Reef is in the Coral Sea Marine Park (Australian Marine Parks).
• Visibility: Day-trip reefs typically 15-30 m (50-100 ft); Osprey Reef 30-60 m per Parks Australia.

Season

• Best months: May, Jun, Jul, Aug, Sep, Oct
• Acceptable: Apr, Nov
• Poor: Dec, Jan, Feb, Mar
• Water temperature: 22–29 °C

May to October is the drier, clearer period (June-September often best); the wet season runs roughly November to April, heaviest December-March, though offshore reef conditions can differ from the mainland. Dwarf minke whales appear June-July; at Osprey Reef hammerheads aggregate in cooler months.

Dive sites (23)

Osprey Reef & Coral Sea

• Admiralty Anchor – 5–35 m, intermediate
• Cobalt Caves – 7–35 m, advanced
• Coral Castles – 5–32 m, advanced
• North Horn – 5–40 m, advanced
• Raging Horn – 8–40 m, advanced

Port Douglas & Agincourt

• Agincourt Reef North – 8–35 m, intermediate
• Chinamans Reef – 8–40 m, intermediate
• G Spot – 10–25 m, intermediate
• Phils (Nursery Bommie, St Crispin area) – 5–25 m, beginner

Northern Ribbon Reefs & Lizard Island

• Challenger Bay – 5–20 m, beginner
• Cod Hole – 10–30 m, intermediate
• Eagle Rock – 3–25 m, intermediate
• Pixie Gardens – 5–12 m, beginner
• Pixie Pinnacle – 5–28 m, intermediate
• Seven Heaven – 3–30 m, intermediate
• Two Towers – 30 m, intermediate

Southern Ribbon Reefs

• Clam Gardens – 5–40 m, intermediate
• North Ribbon Reef 2 – 20–35 m, advanced
• North Ribbon Reef 5 – 15–45 m, advanced
• Steve's Bommie – 5–35 m, advanced
• Tracey's Wonderland – 2–25 m, beginner

Cairns Outer Reef

• Norman Reef (Turtle Bay) – 10–20 m, beginner
• Twin Peaks (Saxon Reef) – 3–18 m, intermediate

Operators (6)

• Mike Ball Dive Expeditions (Spoilsport) – liveaboard, Cairns, Queensland
• Spirit of Freedom – liveaboard, Cairns, Queensland
• Pro Dive Cairns – dive centre, Cairns, Queensland
• Divers Den – dive centre, Cairns, Queensland
• Poseidon Outer Reef Cruises – dive centre, Port Douglas Marina, Queensland
• Tusa Reef Tours – dive centre, Cairns, Queensland

Routes (5)

• GBR & Ribbon Reefs, 5 nights (Spoilsport)
• Coral Sea Exploratory, 7 nights (Spoilsport)
• Cod Hole & Ribbon Reefs, 3 nights (Spirit of Freedom)
• Lizard Island fly-in, Ribbon Reefs & Coral Sea, 4 nights (Spirit of Freedom)
• Ribbon Reefs, Cod Hole & Osprey Reef, 7 nights (Spirit of Freedom)

Site positions are approximate unless marked otherwise and are for orientation only, never for navigation. Many positions are single published GPS readings of unknown accuracy. Always dive with a local operator; conditions, moorings and marine park zoning change.