A dive to the deepest parts of all five oceans Sinkholes don't just happen on land, they also happen in the ocean where they're known as blue holes. And now, researchers say they've found the ...

Aerial view of the Sansha Yongle Blue Hole — the previous record holder — on July 24, 2016 in Xisha Islands, Sansha City, Hainan Province of China. Luo Yunfei/CNSPHOTO/VCG ...