Christopher Columbus believes he can find an alternative route to the far East and persuades the King and Queen of Spain to finance his expedition. But the Sultan of Turkey, who makes a great deal of money through taxing the merchants who have to pass through his country on the current route, sends his best spy, Fatima, to wreck the trip.
Carry on Columbus
History is only slightly rewritten: instead of experienced sailors, there are only convicts whose last and only meeting with H2O was their prison diet of bread and water. And Columbus doesn't have his own map.