Sail Rock (Hin Bai)
A granite pinnacle rising from mid-Gulf, widely rated the best dive site in the Gulf of Thailand and a seasonal whale-shark spot.
- Category
- Diving & Snorkeling
- Entrance fee
- No site fee; boat dive/snorkel day trips from Koh Phangan ~1,500-2,500+ THB depending on dives/gear, as of 2026 - confirm locally
- Hours
- Trips depart in the morning (full or half day); weather-dependent
- Best time
- Best diving roughly May-Sept for visibility and whale-shark chances; seas can be rough Nov-Dec
- Time needed
- Full or half-day boat trip
- Difficulty
- Snorkelling is easy at the surface; the famous vertical 'Chimney' swim-through is for certified divers
About Sail Rock (Hin Bai)
Sail Rock, or Hin Bai, is a granite pinnacle rising out of the middle of the Gulf, and it's widely rated the best dive site in the Gulf of Thailand. That's not marketing fluff, the fish life is abundant and it's a genuine highlight for anyone who gets in the water.
The signature feature is the Chimney, a vertical swim-through that certified divers rave about. Snorkellers aren't left out either: plenty happens right at the surface, and in season there's a real chance of whale sharks passing through.
It's boat-only and a fair way out, so it's a proper day trip. Go in the calmer months for the best visibility and your best shot at the big fish.
Highlights
- Widely rated the best dive site in the Gulf of Thailand
- The famous vertical Chimney swim-through for divers
- Seasonal whale-shark encounters
- Abundant fish life for divers and snorkellers alike
Tips
- Aim for the calmer months for visibility and whale-shark chances
- Trips are boat-only and depart in the morning, so book ahead
- Snorkellers can enjoy the surface; the Chimney is for certified divers
- Seas can be rough Nov-Dec, so check conditions before booking
How to get there
Boat only. Dive/snorkel day boats depart Thong Sala or Chalok Lam pier; ~1-1.5 hours each way