Float-over installation method has been recently used to install topsides onto jacket type of platform. As a viable alternative to the traditional lifting installation method, this method uses a float-over barge to transport and install topsides onto the platform by ballasting operations. This method eliminates the use of heavy lift vessel, and thus is economical for a platform with heavy topsides. The motions of the barge during float-over installation are critical and must be analyzed to ensure successful operations. For the study presented in this paper, the model tests for a float-over barge were conducted on a model following Froude Scaling Laws with geometric scale ratio of 1:50. The model was tested in random wave sea states with varying drafts. The result of the physical modeling study are then analyzed and presented in terms of Response Amplitude Operators (RAOs) for surge, heave and pitch. The results quantify the importance of design parameters such as draft or ballast condition in the response of float-over barge © 2012 IEEE.