Tim Dowling: Can that really be a dolphin on the horizon?

I look upriver, across the expanse of swirling grey water, past a lone canoeist. Suddenly a dark fin rises out of the currentI am on my hands and knees pulling everything out of the cupboard under the stairs. I’ve spread all the stuff – a tent, three sleeping bags, a skateboard, a bag of dusty computer cables, a single boxing glove – across the hall so that no one can pass without experiencing my frustration.“What are you doing?” my wife says. “