So many times I'd go and search through the scientific papers,

looking for the strange thing I'd seen.

And then you'd just come up absolutely blank. There's nothing.

You're going into a place that's under-studied,

and, almost on a weekly basis, you can find out something new to science.

According to the literature, octopus are supposed to be a nocturnal species.

Now, was she more active at night?

It was a little bit scary in the dark.

[whales moaning]

These incredible sounds of the humpback whales

coming through the water.

You're on hyperalert.

[whales hooting]

I couldn't find her. She wasn't in her den.

I'd kind of given up and was going back to the shore.

Something just made me veer slightly to the left.

And there she is...

right in extremely shallow water.

Can't see what she's doing.

These lightning-fast strikes.