Seawatching has been gaining popularity, whether watching from coastal sites or from boats. Many seabirds will only be seen in flight, and viewing opportunities are frequently brief. This is a field guide for birdwatching at sea, and is specifically designed to address the particular problems and limitations associated with this kind of birdwatching. The authors have selected photographs of European seabirds in flight, and complement these with an identification-focussed text. Distribution maps are also included.