This study presents dynamic responses of submerged highly elastic structures, strengthened with cable elements and the fluid interacting with the structure. For this purpose, fluid and structure are modelled with smoothed particle hydrodynamics and finite element methods, respectively. The interaction is satisfied with contact mechanics. In order to simulate the cable, a finite element model with a two-node cable element is used. The stiffness obtained from the cable is added to the structure and the whole fluid-structure system is solved together. The novel contribution of the present study is the coupling a two-node cable element model with the fluid-structure interaction method. In order to validate the numerical method, a set of novel experiments is carried out. In the experiments, cable elements are attached to an elastic structure that is placed in a water tank. Near-fault and earthquake excitations are applied to the tank and the displacement of the structure and the free surfaces of the water are recorded. All the results show that the proposed two-dimensional numerical model is capable of modelling the submerged elastic structure strengthened with the cable under the seismic excitations.