- An investigation is made of several simplifications and hydrodynamic approximations commonly employed in wave force analyses. Alternatives and modifications are sought which improve the resolution of a general Morison approach. This is accomplished by considering two basic arrangements: a vertical cylinder and a horizontal cylinder in progressive waves. The physical differences between the flows are explored, and the results are compared to previous planar harmonic flow measurements. It is found that modifications to the usual Morison approach are required to account adequately for the orbital motions of the fluid and to account for the orientation of the orbits with respect to the cylinder axis.