Maritime decarbonization requires propulsion systems that are low-emission and dynamically suitable for repeated short-route operation. This paper presents a route-inspired, time-domain power-balance assessment of proton exchange membrane fuel cell (PEMFC)-based hybrid architectures for a 1.80 m prototype catamaran. A real ferry operating context in the Suez Canal region was translated into a representative 15 min prototype operating cycle repeated over an 8 h operating window. Three cases were evaluated under the same DC-bus load basis: Case 1, PEMFC + Battery; Case 2, PEMFC + PV; and Case 3, PEMFC + PV + Battery. The PEMFC-battery calculations were based on DC-bus power balance, converter, battery-current, and SOC equations, while the PV contribution was calculated using a shipboard PV power model with PVGIS seasonal irradiance and temperature inputs. The results show that Case 1 eliminates repeated startup deficits through battery support, whereas Case 2 reduces PEMFC loading but cannot remove startup deficits without an energy buffer. Under the best seasonal PV input, July, the PV peak reached 84.88 W, and the PV-used energy in Case 2 was 399.64 Wh. Case 3 increased the utilized PV-bus energy to 450.87 Wh, maintained the final SOC at 0.90, and removed the repeated transient deficits under the adopted ideal power-balance assumptions. Therefore, the PEMFC + PV + Battery architecture is selected as the preferred configuration for the next experimental prototype phase.