The Inland WaterWays division of Van der Velden Marine Systems in the Netherlands has introduced an innovative new retractable tunnel specially developed for inland vessels. Using a unique construction, the Van der Velden® Flex Tunnel offers major benefits to ship owners and operators in terms of speed, loading capacity, manoeuvrability and reduced fuel consumption. Moreover, an overall propulsion efficiency of 10% can be achieved. Water levels are unpredictable and low water levels have serious consequences for inland vessels, as it limits loading capacity and operability.