This paper explores the synergistic use of offshore wind, wave energy, and photovoltaics for maritime hydrogen refueling stations, focusing on their impact on storage requirements. Two Mediterranean locations, eastern Crete and the Galite islands, were selected as candidate locations for installing maritime hydrogen refueling stations due to their high potential in wind, wave, and solar energy. The study employs a Storage-to-Production Ratio (SPR) index, which quantifies the storage needed to maintain a consistent and uninterrupted hydrogen supply to ships year-round, relative to the total annual hydrogen production. Our findings reveal that integrating either wind or wave energy with solar power significantly decreases the SPR, attributed to the low correlation between solar and the other two energy sources. This reduction is substantial, lowering the SPR by up to 20%. Practically, assuming a refueling station with a consistent annual hydrogen supply of approximately 20.000 tons, the synergy could lead to a reduction of the hydrogen storage by 4.000 tons, i.e. 0.2×20.000 tons. On the other hand, combining wind and wave energy in Mediterranean Sea does not contribute to the SPR reduction due to substantial temporal correlation between wind and wave sources.