Generally, inward and outward effects are huge and prime in the rotating components. Based on the working environments of a rotor, the complexity is increased furthermore. Similarly, this work also deals the complicated problem, which is fatigue life estimation of Marine Vehicles’ propeller for different lightweight materials under given Ocean environments by using Ansys Fluent 16.2. The conceptual design of the ship propeller is modeled with the help of CATIA. Fatigue life estimation on the rotor is a key and complex output of this work, so advanced methodology is mandatory for computation. For that purpose, the following advanced methodology has been implemented for this work, which is Hydro Structural Interaction (HSI) and Moving Reference Frame (MRF) techniques are associated in Computational Fluid Dynamics (CFD). Hydro-Fluid properties such as density and operating pressure are used as per the working vehicles’ environment, which has been easily, defined in Ansys Fluent 17.2. Thus this computational platform is perfect to handle hydrodynamic simulations, even though the gird convergence study is conducted for the better outcomes. In the case of structural simulation, the existing materials such as Aluminium alloy and Stainless Steel are used for fatigue life estimation under HSI loading conditions. Finally, the fatigue life estimation of Marine Vehicles’ propeller is extended for composite materials to compare the life of a rotor. Both the Hydrostatic and Hydrodynamic loading conditions are tested on Aquatic Vehicle’s rotor and thereby the suitable material is chosen and given to the future input for real-time applications.