Sheila Hancock and broadcaster Gyles Brandreth tackle their first manual lock and some terrifyingly tight turns, but find themselves relaxing into life at 4mph, and marvel at how secret histories reveal themselves. They visit the Royal Gunpowder Mills, which built its own canal system to transport volatile ammunition - vital to Britain's success in both world wars. 

Starring:

Prunella Scales, Timothy West

Genre:

Documentary