Decarbonization is important for reducing environmental impact and improving sustainability across all commercial enterprizes including hard to decarbonize sectors such as marine. A hybrid seagoing marine vehicle model was created and used to investigate the fuel savings potential of hybrid electric powertrains for commercial fishing boats in Alaska and the sensitivity of those potential fuel savings to component sizing and specific fishery participation. Data collected from the subject conventional diesel-powered boat were used to create and validate a flexible physics-based energy model of the conventional powertrain, which served as the foundation of an adaptable hybrid electric energy model. A linear programming formulation was developed for energy management in the hybrid model and used to optimize fuel savings from the hybrid system.  To generalize the results to a broader population of commercial fishing boats, A Markov random walk method was used to generate duty cycles of entire fishing seasons for boats working in various fisheries over the course of a year. A simple payback analysis considers which powertrain options are financially viable for each year-long duty cycle. Simulation results show that an aggressive hybrid powertrain could result in up to 3 days of full electric operation while a mild hybrid would result in a 50% fuel savings on the same 3-day mission. Missions out to 12 days still resulted in 12-19% savings for those same hybrid powertrains,  but the at-sea recharging and longer transits inherent in longer voyages reduced the maximum savings compared to shorter missions that include recharging batteries at dock.