The maritime industry's significant greenhouse gas emissions highlight the urgent need for cleaner, alternative fuels. This study delves into three emerging maritime fuel technologies: Hydrogen from Proton Exchange Membrane (PEM) Electrolysis, Ammonia from N2-air separation and Haber-Bosch synthesis, and Methanol from Biogas Upgrading. By conducting a comprehensive comparative analysis, this research aims to lay the groundwork for future sustainable fuel pathways. The research employs a multi-faceted approach, combining qualitative case studies with quantitative Key Performance Indicators (KPIs). In addition to standard metrics like Technology Readiness Levels and cost assessments, the study includes unique KPIs such as hydrogen fueling demand and total pathway electricity requirements. Environmental factors like water usage and emissions are also considered, providing a holistic view of each fuel's sustainability.This research offers a nuanced view of alternative maritime fuels, each with unique advantages and challenges. It underscores that achieving a sustainable maritime sector requires concerted efforts, including technological innovation.