Abstract: The challenge of predicting wave propagation for ship-borne communication systems in complex marine environments is addressed by employing a hybrid modeling approach that combines the Finite-Difference Time-Domain (FDTD) method with the Parabolic Equation (PE) method. A joint FDTD-PE algorithm facilitates near-field and far-field domain modeling: the FDTD method is applied in the complex source region to establish a coupled model that includes rough sea surfaces and ship structures, accurately characterizing the electromagnetic wave source. In the propagation region, where only rough sea surfaces are present, the PE algorithm is introduced to effectively enhance computational efficiency for large-scale electromagnetic field calculations. To validate the effectiveness of the method, a comparative study with traditional FDTD and PE algorithms evaluates performance on three dimensions: computational accuracy, runtime, and memory consumption. Results demonstrate that the FDTD-PE hybrid method exhibits higher computational efficiency and lower memory consumption compared to traditional FDTD methods. Additionally, the hybrid FDTD-PE approach shows greater accuracy in comparison to the PE method. This hybrid modeling strategy provides a solution that balances precision and efficiency for electromagnetic wave propagation analysis in complex ocean environments.