Oscillating Water Column devices (OWC) have been the object of many numerical studies, especially mesh-based ones. The peculiarity of these devices is their Power Take-off system, which often involves another phase (air) and requires special effort to be modeled properly. This work proposes a Smoothed-Particle Hydrodynamics (SPH) investigation of OWCs in their standard conception and in a slightly modified version, equipped with a U-shaped duct at the seafront (U-OWC). The novelty of this study is the modeling of a single-phase pneumatic model within an SPH framework (meshless), based on the DualSPHysics software. Hydrodynamic investigation and comparison is presented.