The global energy transition necessitates the integration of offshore and hybrid renewable energy systems to address challenges of sustainability, cost, and resource availability. This study develops a synthetic yet empirically anchored dataset for seven emerging offshore technologies—Ocean Thermal Energy Conversion (OTEC), offshore solar, tidal, wave, floating wind, piezoelectric harvesters, and subsea compressed air storage—across ten geographically diverse marine regions. Real-world anchors were obtained from the International Energy Agency (IEA), National Renewable Energy Laboratory (NREL), International Renewable Energy Agency (IRENA), and other authoritative databases to construct realistic techno-economic parameters such as Levelized Cost Of Energy (LCOE), Capital And Operational Expenditures (CAPEX/OPEX), Technology Readiness Levels (TRL), and sustainability indices. The analysis reveals that offshore solar and OTEC exhibit relatively stable long-term LCOE trajectories, while floating wind and subsea compressed air storage demonstrate the steepest cost-reduction slopes. Regionally, the Gulf of Mexico and Arabian Sea achieve the lowest average LCOEs, whereas the North Sea and South China Sea remain comparatively higher due to harsher installation and maintenance conditions. Correlation analysis further indicates weak but notable relationships between resource potential and LCOE, suggesting that resource abundance alone is insufficient to guarantee economic viability without supporting policies and technology maturation. The findings highlight the potential of hybridized offshore systems to balance sustainability and affordability, while also providing a reproducible framework for scenario analysis of emerging marine renewables between 2025 and 2050.