Blue holes generate a distinctive blue color when seen from above and are typically only a few dozen meters deep.
It was discovered in about 2003 by a local diver who followed a grouper that went into its mouth. The hole was forgotten until the son of that fisherman began working with marine academic Juan Carlos Alcérreca-Huerta, who took soundings of its depth and was surprised by the results.[2][3]
The mouth of the hole is nearly circular, with a major axis measuring 151.8 metres (498 ft), oriented about 10.76 degrees clockwise from North – similarly to the orientation of major faults in the area.[4]
