The local Yucatán fishermen definitely knew they existed—but nobody really knew how insanely deep they were until recently. It was revealed that the second-deepest submerged sinkhole in the world was found just off the coast of Mexico.
The underwater sinkholes east of the Yucatán Peninsula have been called “pozas” by locals, though scientists term them blue holes. These coastal formations, developed from erosion resulting in submerged pits, can get downright scary deep.
It wasn’t clear how deep, until now.
Researchers dove down a blue hole in Chetumal Bay, in the western Caribbean Sea on the Mexico-Belize border, and confirmed that it was the second-deepest in the world. Called Taam ja’ Blue Hole—Mayan for “deep water”—it drops a loony 900.26 feet (274.4 meters) below sea level. Notably, the title for deepest blue hole goes to Dragon Hole (or the Sansha Yongle Blue Hole) in the South China Sea, with its depth of 987.17 feet (300.89 meters)….