This side event will explore how natural capital valuation tools drive the renaturalization of marine infrastructures, transforming grey spaces into blue oases. Experts from finance, policy, and conservation will discuss innovative methodologies such as ecosystem services valuation and natural capital accounting, along with practical tools and real-world use cases. It will highlight how AI and digital technologies quantify the economic and ecological benefits of marine ecosystems and advance ocean regeneration. Additionally, the event will emphasize how these approaches fund large-scale biodiversity regeneration projects, including species reintroduction and habitat restoration, while fostering cross-sector collaboration, enhancing SDG 14 investment, and scaling up restoration solutions. As a practical case, the RegenPorts program promoted by the Port of Barcelona and the BCN Port Innovation Foundation will be presented.