The presented experimental results provide additional data to a previously published investigation of a floating cylinder under regular wave conditions (https://doi.org/10.7488/ds/2627). Three test series are added to investigate the roll response of the water filled structure. This includes a change of the initial position of the cylinder in the wave tank as well as a rotation of the wave direction. The latter was also conducted for the solid ballast option to provide a direct comparison with the water filled cylinder. This research was carried out at the FloWave Ocean Energy Research Facility of the Institute for Energy Systems, University of Edinburgh.