Harbors are designed to provide the safe loading, unloading, and sheltering for the moored vessels as this region experiences high oscillations due to combined effect of wave refraction, diffraction, and partial reflection from the solid harbor walls. An accurate description of the mathematical model is required, to analyze the wave-induced excitation in the harbor. The fluid domain is divided into two regions as bounded and open sea region. Firstly, the mild-slope equation (MSE) is derived for both regions in terms of a potential function using the energy conservation principle. The total wave energy in the bounded region is estimated by using the hybrid finite element method (HFEM), which is used to formulate the mild-slope equation. In HFEM model, the finite element method is coupled with the analytical approximation method to solve the mild-slope equation in both regions. The present HFEM model is utilized to analyze the convergence behavior for the rectangular harbor. Further, the present numerical scheme is implemented on realistic Pohang New Harbor (PNH) situated in Pohang city (Korea) to analyze the regions of strong and weak amplification. The current numerical model is implemented on regular- and irregular-shaped ports or harbors and can be used as an efficient engineering tool for planning and designing of the artificial industrial harbor and prediction of the incident wave response under the resonance condition.