But this week, a Sea Watch Foundation member spotted a pod of killer whales off Pembrokeshire in western Wales.
During the sighting, one of the or case killed and ate a seal pup - in a rarely seen display of their hunting prowess.
Spotter Caroline Webb told the Sea Watch foundation:
‘There was a struggle going on and a pool of blood was spreading on the surface of the water.
‘It had the rounded blunt head of a Risso’s dolphin but the whole thing appeared to be dark and not pale. We saw the head clearly when it came out of the water to go for the seagulls.’
‘It was near a bay where a baby seal was known to have been lying, about half a mile east of Strumble Head.’
Killer whales, whilst rare in this part of the world, have been spotted in the Irish sea before - four were seen swimming near Bardsey Island just two years ago.
Director of Sea Watch Foundation Dr Peter Evans said that the descriptions of the whale and its prey points to it being an orca.
He added that it was probably an ‘immature male or adult’ judging by Caroline’s description.
Killer whales are found across the world, but are much more common in colder waters such as the Pacific Northwest, along Norway’s coast in the Atlantic and the higher latitudes of the Southern Ocean.