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Blue hole
Dragon Hole (Sansha Yongle)
Paracel Islands, South China Sea
No public photo available
One of the deepest known marine blue holes in the world, measured in 2016.
40 m
301 mRecreational limitBathymetry and profile
A funnel opening about 130 m across that narrows with depth. There is no oxygen below about 100 m, so the bottom 200 m are lifeless.
Dashed line: 40 m recreational diving limit
Features
- Layer of water with no oxygen below 100 m
- Studied with robots and probes
- Local legend says the Monkey King took his staff from here
Specific fauna
- Reef fish in the upper 30 m
- Bacteria that live without oxygen at depth