Abstract: A controlling system is used for controlling a state of a floating arrangement comprising plurality of containers, such as shipping or standard freight containers, especially consistent with ISO standard. At least some of the containers comprise a float arrangement having e.g. intra-container water-displacing volumes, such as an inflatable bag, which can be used for displacing water from the container when the inflatable bag is filled or for letting more water entering into the container when the inflatable bag is emptied, and thereby manipulating the buoyancy or draft of the container and thus also the same of the pontoon platform comprising said container(s). The state of the container and thus the floating arrangement can be controlled by operating the float arrangement by the controlling system, such as manipulating the inflatable bags or other state changing means of the float arrangement, such as propellers or supporting means.