This report presents the results of an extensive experimental investigation of the in line and transverse forces acting on smooth, sand roughened, and marine roughened circular cylinders (k/D = 1/50) of identical length to diameter ratio (L/D = 2) placed in a sinusoidally oscillating flow. The drag, inertia, and the maximum force coefficients have been determined through the use of the Fourier analysis. The transverse force (lift) has been analysed in terms of its root mean square value. In addition, the amplitude of the first ten harmonics have been determined. The results are presented in both graphical and tabulated form in terms of the Reynolds number, Keulegan Carpenter number, relative roughness and the frequency parameter beta (= Re/K). Keywords: Oscillating flow; Unsteady flow; Wave forces; Drag and inertia; and Time dependent flow.