In the first of a new series of Rough Science, presenter Kate Humble takes four intrepid scientists to the tropical island of Zanzibar to test their wits and ingenuity against the Indian Ocean.

Frustration builds as the scientists struggle to complete a set of marine challenges without the help of modern technology. With only a few bits of basic kit to help them and a remote beach-side workshop as their base, the team's first test is to mount an expedition to find and explore a shipwreck off Zanzibar's west coast.

They have just three days to build an underwater spy plane which will send images back to their local fishing dhow and they have to call on all their knowledge and skill just to get a clean drink of water.