Digital twin (DT) technology is emerging as a core solution for future marine development and intelligent ocean management. The review systematically reviews digital twin applications in the marine field, clarifies its concept, proposes a five-layer framework, and summarizes key technologies, including sensing, data management, modeling, simulation, and monitoring. It highlights DT’s ability to synchronize physical marine systems with virtual models in real time, enabling simulation, prediction, optimization, and decision-making. The authors further outline challenges and development prospects, showing how DT can support deep-sea resource exploitation, offshore wind energy, marine engineering, vessel autonomy, environmental monitoring, and system reliability assessment.

Fluid–structure interaction (FSI) governs how flowing water and air interact with marine structures—from wind turbines to underwater cables—and is critical for safe renewable energy development. Traditional numerical simulations and experiments require enormous computational resources, yet often fail to capture multiscale turbulence and long-term system behavior. This review highlights how machine learning (ML) is emerging as a powerful solution for analyzing, predicting, and even controlling FSI systems. Key progress spans feature detection, reduced-order modeling, physics-informed neural networks, and reinforcement-based flow control. By leveraging data-driven models to extract hidden patterns and reconstruct flow fields, ML shows promise in improving efficiency, predictive accuracy, and automated control across ocean engineering applications, positioning itself as a transformative tool for next-generation design.

Underwater wireless power transfer is emerging as a key technology for enabling long-duration, maintenance-free operation of autonomous underwater vehicles (AUVs). This review provides the most comprehensive overview to date of magnetic-coupling-based underwater wireless charging, addressing challenges such as eddy current losses in seawater, misalignment caused by ocean dynamics, and the growing need for simultaneous transfer of power and data. By comparing transmitter–receiver coil structures, compensation networks, and control strategies, the research identifies design pathways that significantly enhance efficiency, stability, and tolerance to dynamic marine conditions. The work also highlights emerging simultaneous wireless power and data transfer (SWPDT) methods that could reshape the future of marine sensing and robotic operations.

Machine learning (ML) is rapidly emerging as a powerful tool to improve the safety, reliability, and long-term performance of marine structures exposed to harsh ocean environments. This study presents a comprehensive review of ML and deep learning algorithms applied to marine engineering, highlighting how they enhance structural design, construction efficiency, and real-time maintenance. The work introduces a novel modeling framework that integrates mechanical principles with data-driven algorithms, improving interpretability and prediction accuracy. It also outlines key challenges such as data scarcity, environmental uncertainty, and model transparency, offering guidance for future research. The review provides valuable insights for structural engineers seeking to adopt ML technologies for next-generation ocean infrastructure.

Blue energy—renewable power derived from the kinetic and potential forces of water—has become a key pathway for building sustainable and low-carbon energy systems. This review synthesizes global progress in hydropower, ocean energy, and hybrid offshore technologies, highlighting rapidly advancing wave-energy devices and triboelectric nanogenerators (TENGs) for blue energy. While hydropower is technologically mature, ocean-based energy systems are expanding due to vast resource potential and accelerating technological innovation. The review identifies promising designs for efficient wave-energy harvesting alongside remaining engineering challenges related to durability, cost, and large-scale deployment. Together, these insights provide a roadmap for advancing water-derived renewable energy to support global decarbonization.