The tonnage of the Syracusia, the biggest ship built in the ancient Mediterranean, has been much discussed by scholars. Indeed, the various merchandise the ship carried are detailed by Athenaeus, who relies on a text previously written by Moschion. However, the value of the units of measurements used in Athenaeus' account are not well known. So far, scholars have suggested only either Athenian or Roman units of measurement. The present report aims at exploring the possibility of local metrological systems, such as Ptolemaic or Sicilian ones, as Moschion and Athenaeus respectively lived in Sicily and in Alexandria.