Sustainability in sports tourism has increased in recent years. Sustainability is a particular focus for diving tourism. This paper analyses the meaning of sustainability to German speaking diving tourists to draw conclusions for the development of tourism strategies. Based on a literature review on the importance of sustainability in diving tourism, an empirical study was designed to understand the importance of the topic within the target group. A total of 174 German-speaking diving tourists were surveyed using an online-questionnaire. The subjects were clustered regarding their sustainable behavior. It could be shown that there is a correlation between age as well as gender and sustainable behavior. A conjoint measurement showed that for diving tourists, ecological aspects are more important than the prize of a diving trip. The gained insights can contribute to establish new and more sustainable offers in diving tourism and thus developing this area of sports tourism more sustainably overall.