A pod of up to 28 long-finned pilot whales has been spotted off the coast of Norfolk.
It is the first live record of the species in Norfolk, according to Carl Chapman, the county's cetacean recorder.
But, while he was delighted to see them, Carl said it was actually a relief to then see them go as they headed east on Monday night.
He explained that pilot whales are deep-water creatures, and there were fears the pod, including three calves, could get into difficulties.
Speaking to edp24.co.uk, Mr Chapman said: "They have a history of strandings and my heart was in my mouth. They were horribly close to the beach – only about 800m out from Weybourne at one point."
According to the BBC, he added: "They were initially very confused. They were breathing heavily and poking their heads out of the water to see where they were.
"I phoned British Divers Marine Life Rescue to put them on standby, but thankfully they weren't needed."
Like the orca, the long-finned pilot whale is really a dolphin.
According to Wikipedia, it belongs to the oceanic dolphin family (Delphinidae), though its behaviour is closer to that of the larger whales.
They are very social, family animals and may travel in groups of up to a hundred with a dominant female mostly acting as a leader.
Long-finned pilot whales are very active and can often be seen lobtailing (slapping the water with their tails) and spyhopping (sticking their heads out of the water to look around). The younger ones also breach. Full grown females have been observed breaching, but this is very rare in adult males.
Long-finned pilot whales often strand themselves on beaches – because they have strong family bonds, when one animal strands, the rest of the pod tends to follow.