techniques The excavation of the wreck at Madrague de Giens utilised a number of archaeological techniques common in underwater archaeology. Using an air pump objects were carefully extricated and recorded before they were removed. Important artefacts, including each amphora, had a number attached to them. These numbers were designed to be clearly visible throughout excavation and to remain as cataloguing numbers through processing and the eventual storage of the recovered items. Comprehensive stereoscopic photographic recording was undertaken across the site at a number of levels and the hull was carefully examined and partly dismantled to determine how it was built. After excavation concluded in 1982 the wreck at Madrague de Giens was reburied in sand and left on the seabed. Archaeological significance The wreck at Madrague de Giens is significant not only because it is one of the largest Roman vessels ever discovered, or that its excavation was the first “truly scientific underwater excavation carried out in France”, but because it also reveals important information about Roman art. During the excavations Pomey created a detailed, scale plan of the hull which he then compared with a selection of images showing ships from around the same time period as the wreck. He discovered that in several mosaics the proportions and shapes were identical to his own plans, suggesting three things: firstly, that mosaics "represent ancient ships with much more realism and accuracy than might be supposed"; secondly, that the deteriorated, destroyed or lost parts of the Madrague de Giens wreck (such as the rigging) were likely similar to those displayed in the images; and thirdly, based on the date ranges of the comparable mosaics, "that this type of ship was built to a virtually identical pattern for more than three centuries". Ship construction The dimensions of Madrague de Giens portray a tall two-masted merchant ship with a displacement of 520 tons implying a total cargo weight of 400 tons, one of the two or three largest ancient ships to be found underwater. It was known as a myriophoroi, capable of carrying 10,000 amphorae. A sharp bottom and prominent keel create a “wine glass” shaped hull with a large leeboard. A strongly curved hull profile and the depth of the keel prevented the ship from drifting, enabling it to sail windward. This hull design is characterized by a reverse stempost with a cutwater, enabling the vessel to compensate for its large, non-specialized,