Where is Dragon Hole, the deepest known underwater sinkhole in the world?

Question

Where is the Cotahausi Canyon, one of the deepest canyons in the world and over twice as deep, at its deepest point, as the Grand Canyon in Arizona, USA?

Answer 1

A new exploration of a legendary blue hole in the South China Sea has found that the underwater feature is the deepest known on Earth. According to Xinhua News, Dragon Hole, or Longdong, is 987 feet (300.89 meters) deep, far deeper than the previous record holder, Dean's Blue Hole in the Bahamas.