The harbour started sinking right after completion. There are different views of the possible causes of this process: a geological fault line, which passes some 150m west of the present shoreline, earthquakes along its history, maybe even tsunami waves, the unstable sandy bottom, as well as the sheer weight of the huge structures. Today subsidence is in the order of 5-7m, but already in the first century AD the head of the breakwater was submerged, as is attested by the ships wrecked over it. These wrecks and other remains actually date the phases of decay and the attempts at revival, especially during the Byzantine period.
The best indicator of subsidence are port installations built originally at water level, and now submerged meters underwater. Firstly there are the quays and a pierced mooring stone, now under 5-7m of water. A trench dug by the excavators in an attempt to define the western edge of the entrance channel to the port revealed, that in the 6th century AD (the Byzantine period) a rampart of rubble fill was laid across the entrance channel, in an attempt to renovate the decaying port.
Several ships were wrecked in the harbour, trying to sail in over the head of the sunken breakwaters, which turned into dangerous shoals. Near the entrance channel a large ship had her bottom ripped out, tearing off her lead sheathing. She carried lead ingots with the name of the emperor Domitianus “Germanicus” (end of first century AD) and the name of their mines of origin (in the Balkans). These finds were removed from the site, but elsewhere the cargoes of other wrecks may be seen. One was a large Roman carrier loaded with raw marble, destined to adorn Caesarea with sculptures, sarcophagi (coffins) and other luxury items. All that remains from another shipwreck is a heap of amphorae (clay containers) shards, but they help to date it to the 3rd century AD (26).
Another wreck, dated to the late Roman period (4th century AD), had ballast stones made of basalt and carved as a double cancave trapeze.
In the Middle Ages the ancient harbour went out of use. The Moslem rulers of Caesarea and then the Crusaders reused marble and granite columns from the ruins of Roman Caesarea to build a sea wall, a square tower and a jetty, but the maritime activity never reached its past glory. The medieval construction is of low quality, using cemented rubble reinforced with column shafts. It seems that since the Byzantine period, the bay south of the crusader citadel was used as a semi-protected anchorage.
The new quay was constructed in 1950 by the State of Israel to serve the fishermen of the nearby Kibbutz Sdot-Yam. The metal hull of an old steamer, which was previously used to bring illegal Jewish immigrants to Israel after World War II, was filled with cement and sunk at the northern edge of the new breakwater. Thus the modern quay was also built in concrete, but although only 50 years old, is already disintegrating.
Written by Sara Arenson