Due to the fast development of renewable energy systems and the severe limitations enforced by the marine pollution-protocol, the utilizing of windturbines (WTs), solar generation, sea wave energy (SWE), and energy storage systems (ESS) in marine vessel power systems have been attracting a lot of attention. Hence, amarine vessel power system with photovoltaic, WT, SWE, and ESS can be considered as a specific mobile islandedmicrogrid. Consequently, the main target of this paper is to design a new optimal fractional order fuzzy PD+ I load frequency controller (LFC) for islanded microgrids in a ship power system. Since the performance of the controller depends on its parameters, the optimization of these coefficients can play a significant role in improving the output performance of the LFC control. Accordingly, a modified black hole optimization algorithm is utilized for the adaptive tuning of the coefficients of noninteger fuzzy PD+I controller. The performance of the shipboard microgrid is evaluated by utilizing real-world wind power fluctuation and solar radiation data. Finally, the extensive studies and hardware-in-the-loop simulations are applied to prove that the proposed controller can track the reference frequency with lower deviation as well as it is more robust in comparison with the prior-art controllers utilized in the case studies.