Studies show a 9.3 percent increase in maritime CO2 emissions between 2012 and 2018. In recent years, many strategies have been employed to improve ship efficiency and reduce carbon emissions. In this context, this study aims to identify the most suitable solution among the available maritime decarbonization technologies for application to a Brazilian Navy warship. As a methodology, a tertiary review of the literature and a case study are carried out, with the application of a mixed-method multicriteria analysis for ranking and selection of technologies, based on the opinion of experts from the Brazilian Navy. The case study is based on three research propositions: (i) is it possible for the Brazilian Navy to implement technologies aimed at decarbonization in a Warship; (ii) the results of the studies are generalizable to other Warships with similar sizes and types of voyages; (iii) the Brazilian Navy is able to align itself with the theory of organizational ambidexterity, by implementing new technologies aimed at the decarbonization of ships. The results demonstrate that the use of an internal combustion engine with the application of drop-in biofuels is still the most appropriate choice for the selected warship. The study offers both practical and theoretical contributions to maritime decarbonization by presenting the state-of-the-art technologies and alternative fuels available, as well as their applicability in the naval sector.