Remains of hull planks showed that the ship was made of elm, a wood often used by the Romans in their ships. Eventually, in 1964, a sample of the hull planking was carbon dated, and delivered a calibrated calendar date of 220 BC ± 43 years. The disparity in the calibrated radiocarbon date and the expected date based on the ceramics and coins was explained by presuming that the sample plank originated from an old tree, cut much earlier than the ship's sinking event.