The aim of this research is the design and analysis of underwater housings made of ultra-high performance concrete (UHPC) within the Helmholtz Alliance "ROBEX" (robotic exploration of extreme environments) [1]. Due to the extremely corrosive maritime environment, mainly expensive materials such as titanium, ceramics, special stainless steel and aluminum are used so far for the construction of temporary and permanent research stations to guarantee long-term deployment. In this project the suitability of high-strength concrete with compressive strength up to 210 MPa for underwater pressure housings and constructions is examined to provide a low cost and durable alternative especially for large housings in future.