between the Harappan and Mesopotamian civilisations as early as the middle Harappan Phase, with much commerce being handled by "middlemen merchants from Dilmun" (modern Bahrain, Eastern Arabia and Failaka located in the Persian Gulf). Such long-distance sea trade became feasible with the development of plank-built watercraft, equipped with a single central mast supporting a sail of woven rushes or cloth. However, the evidence of sea-borne trade involving the Harappan civilisation is not firm. In their book Rise of Civilization in India and Pakistan archaeologists Bridget Allchin and Raymond Allchin write: ... (p. 173) the settlement at Lothal ... along the east side was a brick basin. It is claimed by its excavator to have been a dockyard, connected by channels to a neighbouring estuary. ... On its edge the excavator discovered several heavily-pierced stones, similar to modern anchor stones employed by traditional seafaring communities of Western India. This interpretation, however, has been challenged, and indeed the published levels of the basin and its entrance relative to the modern sea level seem to argue against it. Leshnik has cogently suggested that it was a tank for the reception of sweet water, channelled from higher ground inland to an area where the local water supplies were anciently, as still today, saline. We regard either interpretation as still unproven, but favour the latter. ... (p. 188–189) The discussion of trade focuses attention upon methods of transport. Several representations of ships are found on seals and graffiti at Harappa, Mohenjo-daro (Figs. 7.15–7.16], etc, and a terracotta model of a ship, with a stick impressed socket for the mast and eyeholes for fixing rigging comes from Lothal. We have already seen above that the great brick tank, interpreted by Rao as a dock at Lothal, cannot yet be certainly identified. The evidence of sea trade and contact during the Harappan period is largely circumstantial, or derived from inferences from the Mesopotamian texts, as detailed above. (Figure 7. 15 had caption: Mohenjo-daro: representation of ship on a stone seal (length 4.3 cm) (after Mackay). Figure 7.16 Mohenjo-daro: representation of ship on terracotta amulet (length 4.5 cm) after Dales) And Daniel T. Potts writes: It is generally assumed that most trade between the Indus Valley (ancient Meluhha?) and western neighbors proceeded up the Persian Gulf rather than overland. Although there is no incontrovertible proof that this was indeed the case, the distribution of Indus-type artifacts on the