
Cook Island
Byron Bay · Australia
Cook Island Aquatic Reserve sits just south of the Queensland border and north of Byron Bay, accessible from Fingal Head. The island's rocky reef system holds some of the highest coral cover on this stretch of coast, with hard coral gardens on the northern faces in 10 to 20 metres. Common dolphins regularly pass through on early morning boat trips and occasionally interact with divers in the water. Green turtles are abundant and among the most relaxed in the region — resting under ledges and feeding on algae with little concern for divers. Reef fish diversity is notably higher here than at Julian Rocks, reflecting the stronger tropical influence.
Conditions
Depth
5 to 22 m
Open water and up
Current
Usually gentle
Can pick up on the edge
Visibility
10 to 22 m
Clearest in the calm season
Water
19 to 28°C
5mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 25 | 25 | 24 | 23 | 22 | 20 | 19 | 19 | 20 | 22 | 23 | 24 |
| Vis (m) | 8 | 8 | 8 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 8 | 8 |
| Current | Moderate | Moderate | Moderate | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Gentle | Moderate | Moderate |
Your chances of seeing each animal
Green Sea Turtle
Last confirmed Jul 4, 2026 · 29 records
Very likely
Most dives
Common Dolphin
Last confirmed Jul 13, 2024 · 1 records
Sometimes
About 1 in 3 dives
Acerola Damselfish
Expected
Known here, not yet in recent logs
Bicolor Parrotfish
Expected
Known here, not yet in recent logs
Staghorn Coral
Expected
Known here, not yet in recent logs
Longspined Sea Urchin
Expected
Known here, not yet in recent logs
Giant Clam
Expected
Known here, not yet in recent logs
Dusky Dottyback
Expected
Known here, not yet in recent logs
Gear