Impact by an idealized shipping container on a column were observed for tsunami Ã¯Â¬Â‚ow in a large-scale wave Ã¯Â¬Â‚ume modeled at the O.H.Hinsdale Wave Research Laboratory at Oregon State University. Two specimen types, aluminum and acrylic, were tested; and each specimen was tested in two orientations, longitudinal and transverse. The debris specimens were constructed to be 1:5 scaled versions of standard hipping containers with container capacities of one twenty-foot equivalent unit(TEU). Hydraulic experiments were compared with corresponding in-air impact experiments using the same experimental conÃ¯Â¬Âguration to assess the hydrodynamic eÃ¯Â¬Â€ects in increasing the impact force. Experiments were conducted by varying Ã¯Â¬Â‚ow conditions, velocity, nonstructural mass, impact angle, and debris specimen material. Hydraulic Longitudinal Aluminum Test results showed a 10% increase in measured impact force when compared to the corresponding In-Air Test. Transverse Aluminum and Longitudinal Acrylic Tests showed upwards of a 40% increase in measured impact force when compared to their corresponding In-Air Tests. The impact durations measured from the in-air test provided a lower bound for the impact duration measured for the in water tests. Hydraulic eÃ¯Â¬Â€ects were shown to increase the impact duration by an average of 20%. Nonstructural mass was shown to have no significant impact on the measured peak impact force, however an increase of non-structural mass appeared to increase the measured impulse as expected.