The Springwatch team - Martin Hughes-Games, Chris Packham and Michaela Strachan - with special guest Iolo Williams, celebrate the wonderful natural history of our seabirds. Seabirds are a remarkable group of animals. Each species has its own incredible biology and fascinating story. Did you know that in its lifetime, the migratory Arctic Tern will have travelled as far as the Moon and back three times? And that the Northern Gannet can dive into the water at speeds of over 60 miles per hour? For nine months of the year these wonderful birds live out at sea, inaccessible to us in the vast wilderness of the world's oceans but for three special months in the summer, they come to the British Isles to breed in huge numbers - a staggering 8 million seabirds of 25 different species. It is one of the greatest wildlife gatherings on Earth and it happens right here on our doorstep. This is our chance to really get to know these fabulous birds of the sea.