This video says about itself:
Great encounter with a pod of Killer Whales yesterday. The light and visibility were poor, so decided to use the opportunity to experiment with video rather than take still photos. This video is a quick and rough edit of the resulting footage. Filmed at three different locations – Clumlie, Boddam and Grutness – in the south mainland of the Shetland Islands, 17th July 2011.
Orcas make waves to prey on seals: here.