The Colombian Seaflower marine protected area (SMPA) is the largest MPA in the Caribbean. The economy of the main island, San Andres (SAI) relies on tourism. This study conducted 1793 surveys to capture information about tourists’ experience and the value they placed on SAI’s beaches. Tourists considered beaches as the main reason for choosing SAI as a destination and expressed that they would be willing to pay additional money, US$ 997,468 annually, on top of what they had already paid for their vacation to protect SAI’s beaches. The study also showed how beach erosion could negatively impact economically the tourism sector of SAI, reducing revenue by 66.6% (estimated at US$ 73 million annually). This research contributed to the first stage in the development of a payment for ecosystem services (PES) scheme to protect SAI’s beaches. The importance of beaches for SAI and the potential loss of revenue due to beach erosion create an opportunity to incentivize the private sector to invest in natural infrastructure that maintains and protects beaches. This study also informs the potential application of valuation studies for the development of innovative financing instruments, such as PES, to achieve financial sustainability for the MPA network in Colombia.