Samaesan Hole
หลุมแสมสาร
The Abyss
A legendary 85–100m deep sinkhole in the Gulf of Thailand — one of Southeast Asia's most extreme technical diving sites.
Depth Range
85–100m
Site Type
pinnacle
Samae San
Visibility
2–10m at depth
20–27°C (cold thermocline]
Getting There
30 min boat from Samae San
Near Samae San islands
2 Jul
3 Jul
4 Jul
5 Jul
6 Jul
7 Jul
8 Jul
Marine Life
Notable Features
- • 85–100m deep sinkhole
- • Extreme technical dive
- • Deepest point in Gulf of Thailand
- • Collapsed cave system
Best Time to Visit
About Samaesan Hole
The Samaesan Hole is a natural underwater sinkhole plunging to approximately 85–100m depth in the middle of the Gulf. It's one of the deepest accessible points in Thai waters and a pilgrimage site for technical divers using trimix and rebreathers. The hole is believed to be a collapsed cave system. Conditions are challenging with cold thermoclines, poor visibility at depth, and strong currents. This is NOT a recreational dive — it requires extensive technical diving training and experience.
Tips
Trimix/rebreather certification required. Only for highly experienced technical divers. Multiple fatalities have occurred here.
Experience Required
Full technical diving certification. Trimix or rebreather trained. NOT recreational.
Location
GPS: 12.5500°N, 100.9700°E
Learn to Freedive in the Gulf of Thailand
Sites like Samaesan Hole are what the Gulf has to offer. Get certified with us on Koh Samui — train at Sail Rock and Koh Tao in groups of no more than 3, skip the Koh Tao ferry, and dive the best of the region.
New to freediving? Get the free beginner's guide first.