Abstract
The increasing demand for sustainable and long durability power solutions of Unmanned Ocean Vehicles (UOVs) such as Autonomous Underwater Vehicles (AUVs), Remotely Operated Vehicles (ROVs), gliders, drifting buoys, and profiling floats has propelled the research into wave energy harvesting (WEH) methods. This review projects the evolution of Wave Energy Converters (WECs) from their initial mechanical designs to the latest hybrid systems that integrate various methods of energy harvesting. It assesses past milestones, current technological architectures, and upcoming innovations for oceanic autonomous platforms, highlighting design aspects such as miniaturization, hydrodynamics, durability, energy storage and adaptive control. Critical issues including variable oceanic conditions, attachment of barnacles, biofouling, corrosion, low energy density and scalability hurdles are discussed alongside mitigation strategies. Future developments point to hybrid multi source energy harvesting, AI enabled power management, bioinspired designs, and offshore micro-grid docking systems to achieve maintenance free ocean operations. This review places WEH as a transformative enabler for future generation UOVs, unlocking extended autonomy and supporting global efforts for sustainable ocean observation, resource exploration, and marine security.