Method for tanker, preferably parcel tanker, construction, comprising the steps of: - providing a hull having a main deck and having arranged therein at least one hold which is accessible via a hatch opening in the main deck; - providing a self-contained tank module comprising a number of cargo tanks; - arranging in the hold the self-contained tank module to provide a tanker, wherein - the tank module is arranged in the hold such that the tank module and the hull are structurally independent and such that the tank module is removable via said hatch opening of the hold after a period of use of the tanker; - the size and shape of the tank module are such that once arranged in the hold, the part of the tank module that is arranged in the hold fits the size and shape of the hold; and - the hatch opening of the hold is closed by means of the tank module; the method further comprising the step of: - arranging above the main deck an outfitting comprising conduits for loading a liquid to be transported into the cargo tanks (61, 63, 65, 67) of the tank module and for unloading the liquid from the cargo tanks after transport; wherein - once arranged in the hold, the tank module extends above the hatch opening; - tank module support members (37, 39, 41) are arranged between the hold and the tank module for supporting the tank module in the hold, wherein the tank module support members (37, 39, 41) are adapted to allow for relative movement between the hold and the tank module; and - a water resisting construction is provided between the tank module and the periphery of the hatch opening that allows for relative movement between the tank module and the periphery of the hatch opening. - providing a hull having a main deck and having arranged therein at least one hold which is accessible via a hatch opening in the main deck; - providing a self-contained tank module comprising a number of cargo tanks; - arranging in the hold the self-contained tank module to provide a tanker, wherein - the tank module is arranged in the hold such that the tank module and the hull are structurally independent and such that the tank module is removable via said hatch opening of the hold after a period of use of the tanker; - the size and shape of the tank module are such that once arranged in the hold, the part of the tank module that is arranged in the hold fits the size and shape of the hold; and - the hatch opening of the hold is closed by means of the tank module; - the tank module is arranged in the hold such that the tank module and the hull are structurally independent and such that the tank module is removable via said hatch opening of the hold after a period of use of the tanker; - the size and shape of the tank module are such that once arranged in the hold, the part of the tank module that is arranged in the hold fits the size and shape of the hold; and - the hatch opening of the hold is closed by means of the tank module; - arranging above the main deck an outfitting comprising conduits for loading a liquid to be transported into the cargo tanks (61, 63, 65, 67) of the tank module and for unloading the liquid from the cargo tanks after transport; - once arranged in the hold, the tank module extends above the hatch opening; - tank module support members (37, 39, 41) are arranged between the hold and the tank module for supporting the tank module in the hold, wherein the tank module support members (37, 39, 41) are adapted to allow for relative movement between the hold and the tank module; and - a water resisting construction is provided between the tank module and the periphery of the hatch opening that allows for relative movement between the tank module and the periphery of the hatch opening.