It’s 426 feet wide and a whopping 987 feet deep — researchers have determined the massive underwater sinkhole in the South China Sea is the deepest in the world, beating out previous record-holder, Dean's Blue Hole, by over 300 feet.
The deep blue hole is officially called the Sansha Yongle Blue Hole but is more commonly referred to as "Longdong," or "Dragon Hole."
Blue holes — so-named for the contrast between the dark blue waters inside and the aqua blue of the shallows around them — are frequented by divers. In fact, one of Jacques Cousteau's favorite diving spots was the Great Blue Hole in Belize, according to Atlas Obscura. Investigating the sinkhole's depths, Cousteau confirmed that it had originated from a limestone cave formation.
CCTV reports that the researchers used a Video Ray Pro 4 underwater robot to explore the sinkhole, where they found more than 20 species of fish and other organisms inhabiting its upper levels.
Sansha Yongle may yield more exciting discoveries in the near future, as the Sansha city government plans to continue to protect and study the blue hole.