This paper proposes the design and validation of a rate of change of frequency (ROCOF) control scheme for a shipboard marine power system (SBMPS). The SBMPS considered in the paper generates power from conventional diesel energy (DE) as well as from non-conventional wave energy (WE) and solar (photovoltaic) energy (SE). The frequency response of SBMPS suffers due to the poor system inertia and uncertainty of renewable power output. Therefore, in the proposed virtual inertia (VI) control method, the SBMPS uses a flywheel energy storage (FWES) for storage or supply of power according to the requirement as well as for frequency regulation of the SBMS model to maintain the frequency and ROCOF of the SBMPS within the allowed limits, and therefore, to ensure the system stability. The dynamic response of the shipboard power system (PS) using the proposed ROCOF control scheme has been investigated under the influence of different weather conditions and some unpredictable variations in load.