By Tom Mendelsohn
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The impressive mammals travel thousands of miles to the winter breeding grounds surrounding the Kingdom of Tonga in search of a mate.
The whales sing complex songs as a courting ritual and the animals give birth and nurse their young in the Pacific waters.
Thousands of whales make the journey every year creating a breathtaking spectacle.
The giant sea creatures weigh around 36 metric tonnes, and can grow up to 16m in length, yet they are curious and friendly and often let humans approach them.
These spectacular photos were taken by French photographer, Vanessa Mignon, who is passionate about swimming with the enormous beasts.
She said, “I believe that swimming with whales allows you to see how majestic, intelligent and gentle they are.
"I have seen so many people cry with joy after their first swim, who describe it as life-changing.”
The whales travel enormous distances to their breeding grounds in order to escape the Antarctic winter between July and October, and must survive on their blubber reserves for the journeys there and back.
Vanessa said: “It’s even more demanding for the mothers that have to protect, nurture and feed their babies in preparation for the long trip back to Antarctica.
“I particularly enjoy photographing the calves. As you see in the pictures, each one is unique in physical appearance.
"Some are very pale, others quite dark, and each has different markings or scratches on them.
"And even though we usually use the underside of the tail to identify the whales, similar to human fingerprints, some whales are very recognisable because of their body patterns.”
Humpback whales were hunted almost to extinction in the 19th and 20th centuries, but the population is recovering since the practice was made illegal in 1966.
There are now an estimated 80,000 of the creatures worldwide, up from a historic low of just 5,000.