Cathedral (Thetford)
Best time to dive
June to November
What you might see
- BarracudaLikely
- Grey reef sharkLikely
- NudibranchLikely
- Pygmy seahorseLikely
- Sea turtleLikely
- SeahorseLikely
Sightings are seasonal probabilities, not promises - even in peak season nature does its own thing.
Certification & difficulty
Advanced Open Water - advanced conditions (currents/depth); dive within your training.
Snorkelling
Not a snorkel site - Limited - Thetford Reef overall is snorkel-friendly, but Cathedral itself (up to 30 m with swim-throughs) is primarily a dive site, popular for night dives
Safety notes
Easy to become disoriented among canyons/bommies - a safety sausage/SMB recommended; depth to 30 m requires care with no-decompression limits; standard reef etiquette (no touching coral)
Permits & fees
GBR EMC: AU$8.00/full-day, AU$4.00/part-day (2025-26 rate, GBRMPA), typically included in trip price
Permits and operators change - confirm before booking.
Location
Nearest hub: Cairns
This profile is desk research, compiled from public sources - not a first-hand dive report. Coordinates are approximate.

