After a break-up, some people hit the gym; others cut their hair or embark on a rebound relationship. In the aftermath of her own break-up seven years ago, Hannah Pierce, then 30, bought a narrowboat named Argie Bargie. Plunged into life on the water on her 45ft-long boat, she quickly learned to grapple with exploding toilets, diesel refuelling and one constantly repeated question from passing…