This work shows how observation, curiosity and perseverance in the face of a coastal erosion problem in the Colombian Caribbean can become a successful and replicable citizen science initiative. This initiative, developed by one person from the community and advised by experts in the area, consists of the adaptation of a soft protection measure against coastal erosion. The methodology is based on two main aspects: smoothing the topographic profile of the beach and placing a barrier of sandbags on the shoreline, in a staggered order, with a curvilinear arrangement for wave breaking. A second additional sandbag barrier can be placed behind. This paper presents three successful case studies, carried out on part of the coast of the municipalities of Arboletes, Los Córdobas and Santa Marta, even obtaining beach accretion results in the latter. This erosion mitigation strategy is low cost, easily replicable in other coastal environments, always with the advice of experts in the field and frequent maintenance of sandbag barriers.