The sequence in this week's Life of Mammals where David is obviously exhilarated by watching dolphins bow-riding brought back the memory of that experience for me. I've mentioned before that I worked for a summer on whale-watching tours off the coast of the Isle of Mull. I saw plenty of minke whales, harbour porpoises and even a lone Risso's dolphin, but I always managed to miss the huge pods of common dolphins bow-riding, much to my disappointment.

The following year, I went back to Mull on holiday, cycling round the island. While I was staying in a lovely bed and breakfast in Uisken, the owner asked me one morning if I'd like to go out on her son's boat, as he'd just seen a pod of dolphins. The end of her question hung in the air and she was enveloped by a cartoon cloud of dust as I tore out the door, wellies trailing. George had a tiny boat, barely 7ft long, which slammed down onto the water as we bounced over the waves. I was full of excitement, face to the wind and scanning the water for signs of sleek backs. Suddenly, they were all around us. If you've never seen wild dolphins close up, it's very difficult to describe the sheer joy you feel when you see them powering through the water, surfing the pressure wave, twisting and turning upside-down underwater. Their speed and grace and synchronisation with the boat and one another is staggering. They are utterly in control and in their element, and for want of any scientific explanation, appear to be having an absolute blast. I felt like laughing and crying at the same time, and George had a huge grin on his face, too. All too soon, they left us — we were going too slow to be fun for long — but I remember the experience vividly even now.