The problem of handling large pithoi also raises questions of shipping. However, large pithoi are not found in the few shipwrecks of merchant vessels from the Bronze Age. In a recent study of the lading of the ship wrecked at Uluburun in the Late Bronze Age, Lin hypothesizes a cargo of about 20 tons, including 10 pithoi at 3.5 tons, or 0.35 tons each, if filled with fluid at about the density of water. The pithoi were not the chief cargo, which was 10 tons of copper ingots. The ship carried the load easily, with a draft of 1 m. The pithoi were comparatively light, with an estimated total mass of 2.7 tonnes. Not all contained liquid; a few were the first known packing crates, containing fine pottery. Fragments of lids were also found.