A Sustainable Technical Pathway for Hydrogen Implementation in Small-Scale Maritime and Inland Waterway Vessels: Energy, Water, Safety, Lifecycle, and TRL Validation Criteria

The decarbonization of maritime and inland waterway transport requires implementation pathways that go beyond fuel substitution and address energy, water, safety, infrastructure, and lifecycle constraints. This study proposes a sustainable technical pathway for hydrogen implementation in small-scale maritime and inland waterway vessels, using Colombia as a territorial case study. The methodology integrates technological surveillance, national energy-transition assessment, sectoral and territorial analysis, hydrogen pathway selection, water-resource management, safety and regulatory review, lifecycle criteria, and progressive validation under Technology Readiness Level principles. The results identify compressed gaseous hydrogen combined with Proton Exchange Membrane fuel cells and hybrid battery support as the most feasible short-term configuration for small vessels due to its modularity, operational flexibility, and compatibility with decentralized applications. The framework also shows that hydrogen production must be designed as a coupled water–energy–hydrogen system, prioritizing treated wastewater, rainwater, desalinated water, or other non-potable sources to avoid pressure on community and agricultural water demand. Laboratory and prototype validation demonstrated a progressive route from didactic hydrogen systems to small-vessel maquettes and scaled prototypes. The proposed pathway provides an implementation-oriented framework for safe, sustainable, and territorially adapted hydrogen deployment in small maritime systems.