Threats to our ocean are climbing both public and political agendas. Marine protected areas (MPAs) are a promising example of Nature-Based Solutions that can protect diversity while delivering ecosystem services when used with a rigorous evidence-based approach, effective management and the right investment. However, insufficient funding for expansion and effective management of MPAs remains a challenge; one that particularly affects developing countries. During the last ten years, a community of investors seeking positive social and environmental returns in addition to financial, have stepped in to fill the marine conservation financing gap. Innovative governance and financial mechanisms must be explored at all levels to provide adequate, flexible and timely funding for MPA operations. Collaborative management partnerships are proven vehicles through which this challenge can be addressed, by creating a more investable ("bankable") structure around MPAs. The main advantages of these partnerships are to improve entrepreneurial approaches to the management of Protected Areas and, for Governments, to reduce the financial burden on Public Budgets. An innovative and scalable collaborative management approach has been recently implemented in the Dominican Republic for the South East Coral Reef Marine Sanctuary. Blended finance solutions have been used to cover the up-front capital needs and MPA revenues are being generated for MPA management and investor returns, via a range of sustainable finance tools including fees paid by visitors and sales of blue carbon credits. Beyond protecting biodiversity, potential benefits include supporting ocean ecosystems, enhanced resilience to climate change, and providing food and income for local communities by supporting sustainable fisheries and tourism. This approach is expected to be transformative for MPAs, and precedent-setting for marine conservation worldwide. After presenting in detail the context of marine impact investment, the enabling conditions to scale up the Dominican Republic approach is discussed.