Common Tern
Sterna hirundo

Common terns have one of the longest migration routes of any bird, with birds ringed in britain being found as far away as Australia. Most make their way from the South Atlantic, off of the coast of South Africa to Europe each Summer. They are agile flyers and can hover to spot fish before diving on them.
 

1: Lac de Neuchâtel, 28/04/2007.