A hidden world 2.5-kilometre down: How an underwater drone discovered France’s deepest shipwreck | World News

A new era in maritime archaeology has been opened up with the major discovery of a French Navy-controlled shipwreck site at a depth of 2567 meters, far from shore at Ramatuelle in the Mediterranean Sea. According to the official Préfet Maritime de la Méditerranée report, this vessel- dubbed Camarat 4- is the deepest known shipwreck in French territorial waters. The site was mapped out using an A6K autonomous underwater drone and had clear images of a large merchant ship with much of its cargo still onboard. Scientists working on this project through the Department of Research into Archaeology of Underwater Shipwrecks (DRASSM) believe this site is like a scientific ‘time capsule’ because of its six cannons plus almost 200 ceramic containers that are incredibly intact because of the extreme pressure and absence of oxygen created by the depths of the Mediterranean. The artefacts from this ancient site will provide an exceptional glimpse into the trade of goods during the time of the Renaissance.

How the A6K underwater drone mapped the ocean floor in total darkness

The discovery was done using the A6K autonomous underwater drone, which can endure the capacity of the abyssal zone, and the French Navy’s CEPHISMER team.The operational use of the A6K uses side-scan sonar and HD cameras to see in total darkness, therefore being able to take hours of video, mapping the floor of the sea, and identifying things that were later determined to be the 16th-century hull, unlike humans, who cannot go to such depths.Finding a shipwreck at a depth of 2,567 meters is more than just a technical accomplishment; it represents a level of accomplishment that most standard submersibles can’t achieve. It was discovered by the CEPHISMER with the A6K, an advanced autonomous underwater vehicle/drone (AUV) designed to create high-resolution maps of the abyssal zone of the ocean, where pressure is approximately 250 times greater than at sea level. Using sophisticated sonar and photogrammetry, the A6K provided archaeologists with high-definition images to help identify a 30-meter hull in complete darkness.

Why France’s deepest shipwreck remained intact

French officials have referred to the wreck of Camarat 4 as a scientifically significant ‘time capsule’ because it is in excellent condition. In the depths of the Mediterranean Sea, the water temperature remains constant, and there is no oxygen, which means that the typical xylophagous organisms that eat wood (e.g., shipworms) cannot survive there. Therefore, the 16th-century wooden timbers of the ship remain in excellent condition, and the cargo- consisting of about 200 ceramics and stacks of plates- looks as it did when the vessel sank 500 years ago.

Discovery of religious clues in the deep

New evidence and clues have developed about the origins of the vessel through high-resolution photogrammetric mapping conducted by the French Navy. Ceramics found at the sunken site of the ship include many that contain IHS monograms (the symbol of Christ), indicating that this ship may have been transporting goods to or from Christ-related organisations and possibly came from the northern Italian Ligurian coastline.In addition, the merchant vessel was extensively armed with six breech-loading bronze cannons and had a very large anchor and two heavy bronze cauldrons used for cooking to secure its valuable cargo against 16th-century Mediterranean privateers. All of which today remain in situ on the ocean floor.