This study investigates the role of P. oceanica in wave energy dissipation and attenuation under varying wave conditions and vegetation characteristics. A series of numerical simulations were conducted, considering different wave conditions and combinations of vegetation parameters, including leaf height, shoot density, stem diameter, and drag coefficient. The study compared scenarios with and without vegetation and analyzed the impact of each vegetation parameter. The results confirm that P. oceanica significantly increases dissipation and reduces wave height, particularly for low/medium wave conditions. The effectiveness of wave attenuation is enhanced with larger vegetation parameters, while reductions in these parameters lead to a significant decrease in dissipation capacity. These findings highlight the importance of restoring and preserving P. oceanica meadows for effective coastal protection. The study also suggests that the model used may reach saturation for high and long wave conditions, indicating the need for further research. Future work should focus on validating the model under extreme long waves and incorporating a broader range of vegetation characteristics.