Thalassotherapy, a technique that uses seawater, seaweed and marine mud, dates back to antiquity. In conducting this research for a client in the southern margin of the Tagus, we intended to map the offer of this service in Portugal, identifying and describing the services offered by each provider. A mystery shopper study was carried out to analyze the quality of service in the different units. In order to know the target consumer of Thalassotherapy, we used questionnaires and in-depth interviews. We assessed the consumers’ likes and dislikes in relation to the service and gathered the resistances from non-consumers. Subsequently, strategies and objectives were defined in relation to the targets, market sources, positioning and strategy of the brand development, including its physical and psychological identity.