A marine vessel, and a system and method of using the marine vessel, to facilitate the introduction of bulk liquid commodities, such as LNG, into the established and extensive worldwide intermodal transportation system, which is based on containerized shipments. The marine vessel is a specialized vessel, of either ship or barge form, that is capable of holding a large number of ISO-sized intermodal LNG tanks and is configured so as to have at one and the same time characteristics of both a tanker vessel (e.g., a gas carrier) and a container vessel. The intermodal LNG tanks connect to a piping system of the marine vessel and are thereby interconnected in such a manner that allows the interconnected intermodal LNG tanks to behave as if they constitute a typical LNG vessel bulk liquid tank to facilitate efficient loading at a typical marine LNG terminal. The containerized intermodal LNG tanks are capable of discharging liquids to a marine terminal as if in a bulk mode, or of being disconnected from the common interconnection system to allow lift-off discharge of the intermodal LNG tanks at a typical cargo container port so that the intermodal LNG tanks can enter the existing intermodal transportation system for further distribution to the end user by other marine vessels, over-the-road truck, or by rail.