It was a memorable finale to a day out on the Atlantic: a four-metre whale calf gliding past the boat as the divers returned to the Spanish island of El Hierro in the Canaries. Their incredible luck, however, would be made clear hours later, as researchers around the world clamoured for more details after seeing the 47-second video of the encounter online. The divers had unwittingly stumbled across a North Atlantic right whale – one of the...