Underwater Archaeologists Reveal Hidden Scale of Ancient Mediterranean Ports

A new study by researchers at the University of Haifa suggests that traditional methods of estimating the capacity of ancient Mediterranean ports, which relied solely on surviving stone structures like quays and breakwaters, are significantly flawed. The research, part of the SHIPs project led by Emmanuel Nante, proposes that the actual volume of shipping traffic was much higher than previously believed.

The project's innovative approach shifted focus from the shore to the sea, identifying anchorages located outside the stone harbor facilities as crucial for logistics. Many ancient vessels would moor in naturally protected bays, a factor that drastically alters perceptions of the real cargo throughput of ports like Caesarea.

To create a standardized method for assessing ancient harbor capacity, the team developed a four-component analytical framework. This involved studying mooring techniques by comparing ancient ropes and rings with 19th-century sailing ship photographs. They also reconstructed ancient water depths using geological drilling and compared this data with the draft of merchant vessels.

Advanced technologies, including lidar scanning of coastlines and the use of sonar and metal detectors for underwater exploration, were employed. In Tiberias, on the Sea of Galilee, excavations of a submerged pier revealed that ancient concrete structures were operational for much longer than previously thought, from the 1st century BCE through the Byzantine era.

"Estimating a port's capacity solely by its surviving stone quays overlooks the fact that most ships remained at anchorages; accounting for this crucial element sharply increases cargo turnover," stated Emmanuel Nante. This new systemic approach not only provides a more accurate map of ancient trade but also aids in protecting vulnerable underwater cultural heritage sites. The findings were published in the journal Antiquity.