Current ramp designs used in RORO operations have been determined to be structurally inadequate in Sea-State 3. The main reason for this is that when the ramp is loaded with two vehicles, the relative motions between the ship and the discharge facility induce stresses above yield. The objective of this thesis is to formulate the problem and present results that will enable the design of proper isolators. The problem is formulated in terms of the hydrodynamic interaction between adjacent bodies along with structural coupling. The applicability and limitations of strip theory approaches are established through comparisons with three dimensional hydrodynamic analysis data. An analytic model of the ship-ramp-barge system is developed and tested. The results indicate the validity of the approach and establish a procedure that may be utilized for the design of passively controlled isolators.