We think we know our planet,
but hidden below its surface
is a dark and mysterious world.
For me and for other cave explorers, we look into those black doorways
and we see nothing but opportunity.
Mountaineers often say that they climb mountains,
because they’re there.
We go into caves
and go cave diving, because it’s not there.
You never know where the end is.
The fact that I know there are places on this planet that I have been to
where actually more people have walked on the Moon.
The exploration of these caves and the collecting of animals
deep into these cave systems has provided a fantastic opportunity
for us to do some really exciting new science.
The moment your fin tips touch the water and you slide into the water
there is an element of peace, there’s an element of calmness.
If the dive lasts 10 hours, you have to concentrate for 10 hours.
These caves dives are not a few hundred metres in.
They could be several kilometres from where you entered the water.
The bare housekeeping of things are that the easiest way to deal
with, like, a lot of things underwater is to wear diapers,
and we eat underwater.
As long as you take little bites because if you get a little too voracious
then it becomes difficult to breathe in between chewing.
Swimming into these environments that seem lifeless,
just the disruption of the flow of the water alerts these animals that maybe food is nearby
and they erupt out of the bottom,
out of the silt, and suddenly there’s these tiny white spots
swimming everywhere around us.
Almost all of the animals you find in caves
are descended from ancestors that had eyes, but once they colonise the cave
and adapted to life in the cave they lost their eyes,
because they simply didn’t need them. There’s no light, they can’t see anything,
they don’t need eyes.
The environment itself is in some places incredibly fragile.
Often the water looks absolutely crystal clear til the moment you move through this.
Even if there's any silt or dust then that will start to lift off the walls,
lift away from the floors and very, very quickly
the visibility can go from being absolutely crystal clear to being zero.
When something goes wrong your heart rate soars
and the blood rushes to your head. What’s critically important on a cave dive
is that you’re able to immediately turn that back down.
Tell your body that 'emotions, you won’t serve me right now',
and take a deep breath and literally force your heart rate to slow down.
We rely on that sense of feel of the guideline
sliding through your hands and remembering the cave in your visual recognition
as you touch things and feel rocks on your way out.
The guidelines that we use in caves are much in the way of, I suppose, a trail of breadcrumbs.
Without those, it would be very, very difficult
to navigate your way back out.
As I’m finishing a cave dive, on my way out of the cave
I often will stop at the point where there is the faintest hint of daylight
and slowly drift with the flow towards that pinpoint of light.
And when I get closer to the doorway, I think, 'that’s the most beautiful place anywhere.'
When you're floating on the surface of the water, getting ready to climb out,
there is, for me, always a sense of enormous satisfaction.
It's only by having divers who have been able to penetrate deep into these cave systems
that we have discovered these animals and have been able to incorporate them
in our understanding of the evolutionary history of life on Earth.
The desire to understand more about the natural world
drives us deeper underground into the darkness.
Future cave explorers and scientists will reach depths we can only imagine,
answering questions about our evolutionary past
that might surprise us all.