The maritime sector faces increasing pressure to reduce emissions, especially in ports, pushing governments and shipowners towards greener energy sources. Conventional diesel generator (DG) powered vessels experience increased fuel consumption and emissions during low-power demand due to fluctuating loads with changing sea conditions. Integrating battery energy storage can absorb excess power, optimize DG operation, reduce costs, and manage variable loads. Traditional shipboard power systems (SPS) rely on centralized control schemes, which pose the risk of single points of failure, scalability issues, and increased latency due to centralized decision-making. Decentralized control improves resilience and scalability by eliminating single points of failure and enabling local decision-making, which improves response times and system robustness. Although recent research has explored decentralized control strategies for AC or DC-based SPS, there is limited work on hybrid AC-DC SPS architectures. This paper proposes a decentralized control strategy for integrating multiple power sources within a hybrid AC-DC network to optimize their operation. This approach allows vessels to operate in various modes, including full diesel, hybrid, and zero emission, and seamlessly transition between these modes as needed. The effectiveness of the proposed control scheme is validated through simulation and high-fidelity software-in-the-loop (SIL) results in OPAL-RT 5700, demonstrating adaptive power sharing among different resources.