Overview: The Rough Scientists are sent to a nearby wreck which offers a whole new artificial habitat for plants and fish. As in every programme the team are set three challenges. Firstly, Jonathan will need to design and build a submersible, remote-controlled rover to send back pictures from the sea-bed; Kathy’s challenge is to work out how to reach the wreck at low tide, when it will be most visible; while Ellen and Mike have to figure out how to purify the team’s water supply.