A NEEMO aquanaut with engine used to move underwater.
The NASA Extreme Environment Mission Operations (NEEMO) train astronauts for life in space. Living and working in an underwater base is similar to life on a space station. During a 16-day mission, ESA's Matthias Maurer and six crewmates lived in cramped conditions, performed ‘waterwalks’ and had to solve problems as a team to test equipment and techniques for future space exploration.
The underwater base is almost 20 m under the sea off the coast of Florida.