This video from New Zealand is called Summer at Mahia swimming with Moko the bottlenose dolphin.
From the New Zealand Herald:
Moko the dolphin helps locals save whales from beaching
6:00AM Wednesday March 12, 2008
The playful dolphin, who has set up home around Mahia on the East Coast, was the perfect helper on Monday as Department of Conservation worker Malcolm Smith toiled to refloat the mother whale and her one-year-old male calf.
Mr Smith received a call early Monday morning to say the two whales had stranded on the south end of Mahia Beach.
“Generally speaking when pygmy sperm whales strand they end up dying, or they are refloated only to strand again later in the day and die.
“We worked for over an hour to try to get them back out to sea … but they kept getting disorientated and stranding again.
“There is a large sandbar just off the shore so that could have been very confusing for them – they obviously couldn’t find their way back past it to the sea.”
After about four unsuccessful refloating attempts it was becoming highly likely the pair would have to be euthanased.
“The whales were getting tired and I was getting cold when Moko turned up,” he said.
“It was amazing. We’d been working for about an hour-and-a-half when the dolphin came directly up to us.
“[Moko] had them moving parallel to the shore – for about 200 metres or so – within about a minute.”
“The whales were sitting on the surface of the water quite distressed, they had arched their backs and were calling to one another, but as soon as the dolphin turned up they submerged into the water and followed her.”
Moko led the whales about 200m along the beach towards the headland then led the pair all the way out to sea.
“The things that happen in nature never cease to amaze me.
“It was looking like it was going to be a bad outcome for the whales which was very disappointing and then Moko just came along and fixed it.”
Mr Smith said it was quite possible Moko had heard the whales calling.
“She obviously gave them enough guidance to leave the area because we haven’t seen them since.”
Moko however was seen straight after – the playful dolphin swam straight back close to shore to play with local residents.
Moko is a bottlenose dolphin.
214 Environmental Organisations Lobby New Zealand Government Over Rare Dolphins: here.