In the National Maritime Museum in Haifa, a reproduction of a Roman maritime mosaic hangs above a scale model of a Roman grain ship. The mosaic — a copy of the type found decorating the floors of maritime collegia and wealthy houses at Ostia and other Roman port cities — shows the sea as Romans imagined it: dense with fish and marine creatures, alive with the visual abundance that the Mediterranean provided, a merchant vessel moving through a world of tuna, dolphins, an octopus, a whale. The sea in Roman mosaic art is not threatening; it is productive, teeming, the source of food and commerce and the medium through which the empire connected its parts. Below the mosaic, the grain ship model shows the vessel that made this connection real: broad-hulled, square-sailed, designed not for speed but for capacity, the workhorse of the most important supply chain in the ancient world.