This video is called White-beaked dolphin (Lagenorhynchus albirostris).
From Wildlife Extra:
Wildlife guide spots more than 1,000 dolphins
Mega fauna included dolphins, whales and basking sharks
Once a week, Paul Semmens was able to show the passengers the exciting marine mega fauna that could be spotted on the way to the Isles of Scilly, including dolphins, whales, basking sharks and sunfish. But this was not just an exercise for tourists, he was also recording the observations as part of an ongoing survey of what occurs in Cornish and Scillonian waters.
With improved weather this year compared to last year, a wealth of wildlife was spotted. The total for 2010 was an impressive 1,291 animal sightings (compared to just under 800 in 2009), which comprised of:
‘It was great to see so much more than last year,’ said Paul, ‘and especially to pick up the rare white-beaked dolphin.’
The white-beaked dolphin is a northerly occurring species in the Atlantic and Cornwall is at the southern edge of its range.
Highlights included breaching basking sharks
Paul’s other highlights included a lunge-feeding minke whale, bow-riding Risso’s dolphins and breaching basking sharks. Basking sharks can occasionally be seen breaching (leaping clear of the water) particularly when they are in groups when it it is thought it may be some form of courtship display.
Paul says: ‘It’s amazing that for such a normally slow-moving fish they can get enough momentum to hurl themselves completely out of the water, though their landings are far from elegant!’
Survey of 20 years of Cetacean strandings around Britain: here.
Record number of whales slaughtered in the Faroe Islands: here.