This blue hole, now known as the deepest known, is connected to the Caribbean

The "Taam Ja' Blue Hole," located in Chetumal Bay in Mexico, is now recognized as the deepest underwater blue hole ever identified with a recorded depth of at least 1,378 feet (420 meters) below sea level. This finding surpasses by 479 feet (146 meters) the depth initially measured in 2021 and by 390 feet (119 meters) the previous record held by the Sansha Yongle blue hole.


Scientists use a device called a CTD, which measures conductivity, temperature, and depth to transmit real-time water properties via a cable. This technology has revealed that the bottom of Taam Ja' has not yet been reached, despite the already impressive depth.

The CTD has also highlighted different water layers within the blue hole, including one below 1,312 feet (400 meters) whose temperature and salinity conditions resemble those of the Caribbean Sea. This may indicate that Taam Ja' is connected to the ocean through a hidden network of tunnels and caves.

Blue holes are vertical water-filled cavities formed in coastal regions where the bedrock is soluble, such as limestone, marble, or gypsum. They are created when surface water seeps into the rock, dissolving minerals and expanding cracks, until the rock collapses.


Initial measurements of the Taam Ja' Blue Hole were taken using an echosounder, but this technique has limitations within blue holes due to water density fluctuations and the unpredictable shape of the cavities, which may not be perfectly vertical. Furthermore, the CTD instrument could not reach the hole's bottom, stopped at 1,378 feet due to a possible current or an underwater ledge.

Scientists are now aiming to determine the maximum depth of the Taam Ja' Blue Hole and explore the possibilities of this interconnected system of underwater caves and tunnels, as well as the biodiversity that might be found there.