The American Civil War stretched far beyond the battlefield, into American rivers, along coastlines, and out into the world's oceans. Scientific data combines with computer graphics to drain the waters and investigate a conflict that re-wrote the rules of warfare forever.

Draining Lake Michigan uncovers Chicago's secret history. The latest sonar technology exposes a catastrophe that kills 300, solves a tragic Christmas mystery, uncovers a game-changing naval training programme from World War 2 and reveals an engineering marvel that stops the fastest growing city in the world from choking to death.