21 March 2017 Last updated at 22:56 GMT
James Wright, the curator of the National Marine Aquarium, said it was "very surprising" to see the whale in Devon.
He added: "We would expect to see four or five around the Scottish Islands, but not necessarily around here.
"It's looking more like it's actually quite enjoying the area and feeding.
"They tend to move to the colder waters that are more productive, where they are catching smaller fish to feed on, and then they move to warmer waters where the calves are born."
A humpback whale spotted in Start Bay, South Devon, is still drawing curious crowds.