Underwater surveys on the seabed near Tel Ashqelon exposed the remains of basalt hourglass millstones (“donkey” millstones), limestone oil-press weights and a round kurkar stone. The millstones and oil-press weights were brought to the coast to be used for mooring the portable wooden winches, used to haul boats and small ships out of the water for docking and repairs. This system would have functioned between the Roman and Crusader periods, mainly during the Byzantine period, when the city of Ashqelon was a hive of economic activity.