Mapathons and hackathons are short-lived events with different purposes. A mapathon is a collaborative effort for collecting geographic data in unmapped areas, while hackathons are focused on application development. Mapathon outputs need to be high quality to be reusable, but often, when applications are later built on top of map data, there is a mismatch between data collected and application requirements. We conducted an international collaboration project aiming to address this situation by creating a circular process where geographic information is collected in a mapathon and later used in a hackathon. Based on user feedback this cycle can be repeated so the collected data and developed applications can be improved. In this event report, we describe the two mapathon-hackathon cycles that were part of our pilot to validate that process. We present their outcomes and some lessons learned. We focused on the so-called “blue economy” (i.e. the sustainable use of marine and ocean resources for economic growth and improved livelihoods in coastal areas.) as the target domain for this pilot. Data for carefully selected areas of the South African coast was collected through in mapathons and later use in hackathons. The mapathons were held in South Africa, and the hackathons took place in Brazil.