An ocean going transport vessel 11 having a pair of hulls 13 15, supporting a first deck 17 located above and extending across the hulls 13 15 toward one end, and forming a structural link between the hulls 13 15. Each hull 13 15 includes a further deck 65 67 extending from the first deck 17 to the other end of the hulls 13 15. Ballast tanks allow adjustment of the draft and trim of the vessel 11. A void 115 extends between the further decks 65 67 and associated hulls 13 15 for stowage or suspension of a load, frame, or deck. The further decks 65 67 extend longitudinally beyond the hulls 13 15 as cantilevered decks 95 97 which each include a docking point 207 arranged to support the vessel by the cantilevered decks, by the docking point 207 resting on a structural support.