Floatover barges are used for the installation of topsides onto jacket platforms recently. In this study, a frequency domain analysis was performed for a float-over barge subjected to random waves. The excitation forces acting on the floating barge were derived by Froude-Krylov approach. In this paper, seven different sea states were specified for the analysis and the results are presented in terms of Response Amplitude Operators (RAOs). Three motion modes were analyzed namely surge, heave and pitch. The results are presented and conclusions arrived at. The resulting RAOs decrease with an increase in draft while longer wave periods are associated with larger surge, heave and pitch responses. The findings provide guidance for the conceptual design and development of such structures. © 2011 IEEE.