Synthetic biology (synbio) scientists have identified islands as potential environments in which to trial the release of approved gene drives in the future for conservation and biosecurity purposes. However, islands, and their interconnected waterscapes, can connect as much as they contain. The Torres Strait Islands stretch between mainland Australia, of which they are a part, and Papua New Guinea. The Straits' water facilitates transport and fosters customary connection and trans/national notions of kin. In this watery world, how might Torres Strait Islanders' understandings complicate and/or contribute to (synbio) scientific concepts of islands as contained, ‘watertight’ field sites? And how is a changing climate and rising sea levels impacting identities in the Torres Strait and relationships in the region? As intra‐ and inter‐national island anthropology, this article considers how synbio approaches to water may engage with the hydro‐history and fluid future of Torres Strait Islander identities and cross‐cultural socio‐environmental responsibilities.