The Transport Barge is an unarmed transport ship, that allows land units to cross the sea. Once a nation has developed File:Science Research Icon.png Science 1 (Written Word) and owns at least one Dock, land units will automatically embark on a Transport Barge, when ordered to cross sea (e.g. ordered to move to another landmass). The unit's hit point percentage is transferred to the transport – embarking a damaged unit will result in an equally damaged transport. A unit cannot attack nor use any of its active or passive abilities for as long as it is embarked.