John Hopkins

As they loom into focus, Nan takes in their incredible size, their wide, fan-shaped tails, the deep grooves that run along their pale throats, the distinctive geometry of their immense, curved backs.

Despite their vastness, they move serenely.

And yet, Nan doesn't let her guard down.

Years of experience have made her feel comfortable around whales, but that doesn't mean she takes her safety for granted.

On one occasion, while filming two female humpbacks, Nan was charged from behind by a juvenile male.

It's a miracle she wasn't crushed to death.

Near misses like this are a reminder that no matter how intelligent they are, no matter how sophisticated, whales are still wild animals, unpredictable and exceptionally powerful.

With her GoPro camera strapped to her head, Nan watches the whales from a safe distance, taking breaths at the surface when she can, recording the footage the director asks for.

And that's when one of them, a male by the gargantuan size of him, makes a sudden, unexpected movement.

He lifts his head, and with a downward pulse of his enormous tail fluke, begins advancing towards Nan.

At first, she just watches, waiting for the animal to stop or turn.

Nan's hand meets the tip of an elongated, snout-like jaw.

She absorbs the force of the whale's momentum.

But instead of being knocked aside as expected, she feels herself being swept up as the animal keeps swimming forward, pushing Nan through the water like a piece of debris shoved along by a bulldozer.

Sharp barnacles slice into Nan's skin and her body is rattled.

She's blindsided, but also captivated.

She's never experienced this kind of sustained physical contact with a whale before.

She can see up close the color variations of his skin, feel its leathery toughness.

Note the distinctive white scar that marks the top of his head.

As a marine biologist, it's awe-inspiring.