The Indus civilisation's economy appears to have depended significantly on trade, which was facilitated by major advances in transport technology. The IVC may have been the first civilisation to use wheeled transport. These advances may have included bullock carts that are identical to those seen throughout South Asia today, as well as boats. Most of these boats were probably small, flat-bottomed craft, perhaps driven by sail, similar to those one can see on the Indus River today; however, there is secondary evidence of sea-going craft. Archaeologists have discovered a massive, dredged canal and what they regard as a docking facility at the coastal city of Lothal in western India (Gujarat state). An extensive canal network, used for irrigation, has however also been discovered by H.-P. Francfort.