Oceans, lakes and rivers, dynamic and vital ecosystems, face increasing threats from climate change. To ensure its sustainability, there is an urgent need for technologies that promote responsible and sustainable human-water interactions. Water sports engagement fosters mental and physical health benefits, as well as environmental care when responsible practices are encouraged. Although prior work has investigated how interactive technology can support sports practice to make it sustainable, water sports are less explored due to the unique technical challenges they pose. Hence, there is an opportunity for human-computer interaction (HCI) to explore how interactive technology can be adapted to the dynamic, unpredictable nature of outdoor water sports to foster water conservation and ocean sustainability. We argue that by exploring the design of interactive water sports experiences through a soma design lens, we will better understand the intricate synergy between our bodies and the felt and lived body of water, hence, supporting meaningful body-water interactions. We aim to engage researchers in exploring the potential of soma design in the context of water and water sports guided by preliminary posthumanist water frameworks. The workshop outcomes include a design framework supporting engagement in outdoor water sports to foster sustainability through soma design. Insights from the workshop will be documented in a future academic publication to advance the WaterHCI field.