For a while there, it looked like a blue hole in the South China Sea had edged Dean’s Blue Hole in the Bahamas as the world’s deepest blue hole.
That record — in one sense — might not be quite correct, according to champion freediver William Trubridge, organizer of the annual Vertical Blue freediving competition.
Trubridge came across some data that shows the “Dragon Hole” in China isn’t a vertical shaft but one that is shaped more like a comma.
As he wrote in a recent Facebook post:
“I just came across this graphic indicating that it is not a vertical shaft, and that the deepest point that can be measured from the surface might be less than the 203m of Dean’s.
“There are of course many deeper non-vertical holes in the world, such as some of the Yucatan cenotes and the 404m deep Hranice abyss in the Czech Republic, but the distinction of Dean’s is that you can hang a vertical line from the surface all the way to the bottom without it touching the sides. I had thought that was the case as well with this new hole in China, until I saw this graphic as part of a research study.”
For more info about the shape of China’s Dragon Hole, check out nature.com.