Particle-based methods are one of the strongest candidates for tackling challenging fluid-structure interaction (FSI) problems. This is due to their proven abilities to naturally capture highly nonlinear shear forces or free surface deformations together with dynamic rigid body motions and/or structural deformations in the problem domain. To investigate these potentials and develop consistent particle based numerical schemes, the present study focuses on modeling both rigid body motions under different wave climates and flow induced deformations on solid structures using different particle method strategies. An in-house Weakly Compressible SPH (WCSPH) scheme [1] is used to investigate the passive rigid body motions of floating structures under a variety of wave excitation. As for the two-way FSI modeling cases, a coupled SPH and Peridynamics (PD) numerical scheme is developed to determine the fluid flow and solid deformations, respectively. To investigate dynamic rigid body motions under external wave forces acting on a Point Absorber Wave Energy Converters (PAWECs) is simulated. After validating the numerical wave generation process, heave, roll and surge motions of floating bodies are examined under constrained and coupled degrees of freedom applied to the structure. The obtained results indicate that the developed SPH solver can simulate dynamic rigid body motions of floating structures under various external wave loads. To leverage the modeling capabilities of particle methods and enable comprehensive particle-based simulations of real-life scenarios involving extreme interfacial deformations in both fluid and solid phases, we introduce a surface normal updating algorithm integrated into our previously developed hybrid SPH-PD solver [2]. This advancement potentially allows for the investigation of dynamic hydroelastic responses, post-failure behavior, and debris evolution within a unified framework. When material failure occurs, it generates new surfaces and new surface particles. Our algorithm employs straightforward geometry checks to identify surface particles and update their surface normals with sufficient accuracy. Figure 1 presents a post-failure snapshot of a submerged elastic solid, from a simulation of flow past an elastic beam positioned downstream of a rigid cylinder.