Diving Into The Darkness (2024)

[bunniefuu]

[pensive music playing]

[regulator hissing]

[ominous music playing]

[pensive music playing]

[regulator hissing]

[Heinerth] Cave diving is often referred

to as the world's most dangerous sport.

But is it a sport?

[pensive music playing]

It's the closest thing I can think of

to going to another planet.

It's this interesting yin-yang

of light and dark, of beauty and danger.

Cave diving is like swimming

in the veins of Mother Earth.

I'm literally swimming

through water-filled passages

beneath your feet.

And these caves

are like museums of natural history.

We can learn about

where our drinking water is

and how we can protect it

for the next generation.

[pensive music playing]

We can learn about Earth's past climate.

We can learn about ancient civilizations

that have left artifacts.

We can learn about the unique animals

that live in the darkness

of an underwater cave.

When you're exploring a cave,

you must solve

all of your problems underground,

underwater, with no mission control

to call for help.

[ominous music playing]

There are a lot of physical risks.

The silt can rain down from the ceiling.

It's also easy to get lost.

You can also get trapped.

Anything can go wrong

at any time with your gear.

It's critical to know when to turn around.

I know a lot of people

that didn't do that.

I swim through the graves of my friends

all the time.

I've lost over a hundred friends

to technical and cave diving accidents.

You really ask yourself,

is this something I should be doing?

Is this fair to my family?

Do I wanna take these risks?

[regulator hissing]

But in those dark, confined spaces,

I'm happy, I'm comfortable,

I'm in my element.

But I am scared.

I'm not fearless.

[thunder rumbling]

The day that I'm not afraid

about what I'm doing

is the day that I should hang up my fins.

[pensive music playing]

I'm not in this for adrenaline.

I've learned so much

about the plumbing of the planet,

but also about myself through cave diving.

I think cave diving

is a metaphor for life.

We all have to face change

and uncertainty.

[regulator hissing]

Humanity needs people that push

on the edges and step into the darkness.

That's how we evolve.

Jill's been diving at the cutting edge

of cave exploration for so long.

You know, she's had this stellar career

of filmmaking, exploration, and adventures

with all the big names around this planet.

Jill literally wrote

the book on cave diving.

She makes documentaries,

she's an excellent photographer.

She's an author, she's a public speaker.

I think by 2001, she was probably...

the world's best female diver, period.

Forget "cave diver." I'm just talking

about "underwater explorer."

She's there because of

the excitement of exploration,

the satisfaction of curiosity.

Jill always...

I guess she needed to see

what was around the next corner.

She was always very curious.

I could easily say that she was

an explorer from the beginning,

and same as she is now.

[pensive music playing]

[Jang] Our parents

always took us out on hikes.

The Bruce Trail

was a big thing that we enjoyed.

[Heinerth] I loved hiking

the trails, but even more,

I loved climbing down

into those cracks and crevices

and looking around

in this three-dimensional,

below-ground space.

Those were my first experiences in caving,

and often those were cozy,

comfortable, small places.

We had a set of National Geographics

that were gifted

from my grandmother and grandfather.

From the light of a bare bulb,

I would go through these volumes,

page by page.

Those pages showed me

what was possible for me in the future

and inspired me to study and learn

and create a future

where I could be an explorer, too.

[alarm ringing]

[intriguing music playing]

[radio static on TV]

[man on TV] Launch commit. Lift off.

We have lift off with Apollo 14.

[Heinerth] You know, back in the day,

astronauts were heroes,

pushing the envelope of human physiology.

Just the scale, the magnitude,

all that technology.

[astronaut speaking indistinctly

over radio]

[Heinerth] It was like you were looking

through this peephole in history,

seeing something so incredible.

I knew I had a burning desire

to be an explorer.

I was so excited and thrilled.

I ran home and couldn't wait

to tell my mom about the experience,

the thing that I had just seen.

You know, "Mom, I wanna be an astronaut.

I'm gonna be an astronaut."

And then when she told me no,

it was like,

"Oh, like, am I not good enough?

Am I not capable? Like, what is it?"

She's like, "No, there's

no space program for Canadians.

There's no women astronauts.

It's, like, there's no place

for you there."

And it was discouraging.

I thought, "Well, what can I do?

How can I be an explorer?"

[pensive music playing]

Watching and seeing Jacques Cousteau

on TV was that pivot point, really.

Here he was sailing around the world

to fantastic places

and then going underwater

with this wild-looking technology.

Breathing underwater,

and then encountering, like,

sharks and fish and whales.

[whales cooing]

And that captivated me.

And I thought,

"If I can't explore outer space,

if I can't be an astronaut,

maybe I can explore inner space

and the magical depths

of the ocean instead."

My first real cave diving expedition

was the Huautla expedition in 1995.

[dramatic music playing]

Huautla is situated

in the Sierra Mazateca Mountains,

and there's a cave system

inside the mountain.

So if you peel away

the face of that mountain

and you look inside,

you've got, like, this whole network

of tunnels and spaces.

And if you enter a hole

in the top of the mountain,

you might be descending down on rope

or climbing down a waterfall

deeper and deeper into the earth.

And the year before we got there,

that's how the explorers

were getting into the system.

So when I went in 1995

with that very same team,

we decided to work from the bottom up.

We were seeing the pieces

of this puzzle come together,

and one of the biggest unknowns

was this resurgence.

If we could dive in through that,

come up into air-filled passage,

maybe we could just connect

those two together,

and at that time we would have ended up

with roughly the world's deepest cave.

[Heinerth] The expedition got harder

and harder in a series of stages.

I mean, just getting there

was tough in the car,

and we were exhausted

after four days of driving and car repairs

and getting up into the mountains

to an altitude where the car

could barely drive up the incline.

And it was hot, and there were bugs,

and the winds were so strong

that they would blow away your tents

if you weren't in them.

But then we experienced mudslides.

The rainy season came a bit early.

That shallow streamway

between base camp and the cave opening

would periodically be just filled

with this rush,

a tsunami of water down the canyon.

It felt like the physical hardships

were, at times, just too much to bear,

and that was even before we went

into the cave to go diving or surveying.

We didn't have enough burros

and people to carry everything we needed,

so the first and easiest choice was,

"Leave Jill's diving gear

on top of the mountain.

She's not gonna use it.

She's gonna have to do other things

during the project."

So Paul and Noel ended up

doing all of the exploration diving.

I got involved in supporting the base camp

and surveying dry cave,

and doing other things.

But as the dives progressed

and we reached some real physical hurdles,

Noel got to the point where he said,

"I've done everything that I can do,

and I've reached my psychological limit."

Noel was an experienced cave diver,

cave explorer, and a physician.

He was our expedition doctor.

And at that point,

either Paul could dive solo,

or there would be no more diving,

and we'd just dry cave explore,

or, in that split second,

I had a chance to say, "I wanna do it."

And that's what I did.

I said, "Hey, I could fit Noel's gear.

We don't even have to go get my dive gear.

I can wear Noel's diving gear.

I'd like to have an opportunity

to explore this cave."

-And I remember Bill's look like, "Really?

-[pensive music playing]

What makes you think that you've got

the chops to pull off this dive

when Noel says it's too much

and he feels it's not safe to go on?

Why are you convinced

that you're not gonna die in there,

and I'm gonna have to carry your body

out of this canyon back up

and explain to your family what happened?"

Because just a year earlier

in the very same spot,

one of their teammates had died.

And it was a friend, a dear friend,

and they had to carry his body,

something that took 12 days.

That pall hung over that expedition,

and it informed everything that we did.

And I thought,

"Whoa, that didn't take long."

This is business.

This is really serious.

This is not just some fun lark

on a travel destination.

This is life and death.

What I wasn't sure of

when that conversation happened

was the level of her discipline, you know?

Was she the one that was gonna get

to 68 meters depth and panic,

you know, and take Paul down with her?

This is not some Boy Scout badge

that you put on your arm and use

to be some status symbol, you know?

This is deadly sh*t.

You go in there,

and there is a finite chance

that you are going to die

if you don't do things just right.

If you have somebody who's just gung h*

without considering the consequences,

that was what I was looking for.

Was this somebody who's just,

"I wanna make a name for myself

by getting in here

and pushing this

to some spectacular limit"?

[clears throat] Or is it

somebody who says,

"You know what,

the goal here is to get data

and not get anybody hurt"?

And by the time the sun came up,

Bill said, "I'll support you.

I'll help carry your gear.

I'll get you there

and do whatever you need to do.

I'm willing to give you a chance."

And that changed my life.

[tense music playing]

On the biggest dive,

we needed everybody's help.

The river was swollen

between the base camp

and the opening of the cave,

and it was very dangerous,

even to transport all the gear, the tanks

and everything to begin the dive.

And then as Paul and I

got ourselves prepared,

got all our tanks organized,

the moment that it was time to go,

the water started to rise.

Dirty water started

to flood into the cave,

and the current turned to reverse.

We had a split second

to make a decision to go or no go.

And I looked at Paul, and he said,

"Dive, dive, dive,"

and disappeared under the surface.

In that moment,

I remember thinking to myself,

"Are you an explorer or not?"

And I went for it.

And I dove underwater,

racing against

that flowing current of dirty water

that was running into the cave system,

and swam as fast as I could

to keep up to Paul.

It's like the die was cast,

and I was on autopilot.

It was happening.

[dramatic music playing]

[regulator hissing]

So we surface in this pool

with a waterfall

cascading down on top of us.

But at this point,

in order to continue on,

we needed to climb up over the waterfall,

get our gear up there, and continue.

[Stone] I mean, it's as close to,

you know, Jules Verne as you're gonna get.

The rest of the world disappears,

and you are an explorer.

Once we'd gone through that whole

ordeal and gotten into that upper pool

and continued into the water

that was clear...

I thought, "Okay, this is it.

This is the edge of the unknown.

I am touching the void and going forward."

My heart is racing.

There's no map, so you're gonna make it.

[music intensifies]

[regulator hissing]

When I look back on that dive

into the deep passages,

we ended up too deep

for the traditional breathing gases.

The sounds in my mind were,

"Ooh, turn around, turn around."

It was that distance pressure.

"Whoa, we're a long way from home."

And when those nerves

start to creep in, it's really time to go.

[suspenseful music playing]

You have to be willing

to get within a hair's breadth

of complete success,

but also know when to turn around.

When I got out of the dive

and I reached the surface,

the first thing that I saw was Bill Stone

crouched by the side of the water,

like a mother hen, and he looked down,

he's like, "Oh, thank God."

We have three rules

on any expedition that I organize.

One is that nobody gets hurt.

Second one is everybody has

a memorable time.

And the third one is

you come home with new data,

as much as you can get safely, right?

And so if you take all three of those,

we hit them all.

What they stopped at,

at 600 meters in and 68 meters deep,

was a gigantic underwater tunnel

carrying this subterranean river.

So that remains an open question,

and nobody has been back

to continue that work.

So it's still out there.

When I first met Jill,

I thought that she had skills.

They were undemonstrated to me.

So it was somewhat of a gamble

taking her on that trip.

And, you know, the end result is

she kicked a*s and did a great job,

and was good at focusing

on getting the information that we needed,

the data that had to come out of there

so that we could think about,

"All right, how do we plan a return?"

So to me that showed that she had,

you know, the right stuff, you know,

the astronaut quality that we seek

when we're talking about people

doing this kind of stuff.

[Heinerth] Working with Bill Stone in 1995

gave me an opportunity to explore

what we thought could be

the world's deepest vertical cave system.

So in 1996, I turned my attention

to what we thought would be

the longest cave system in the world.

[pensive music playing]

[Kakuk] Jill's forte has always been

as a coordinator,

getting the right people

in the right places.

She played a big part in that,

as well as going out there

and making discoveries on her own.

She wanted to be more involved

in cave diving.

She wanted to be

more involved in discovery.

She knew what her future was gonna be.

There wasn't anything gonna stop her

from getting there.

[Heinerth] It was very affirming

to finally push the envelope

and be leading instead of following.

I began to recognize

how important my viewpoint

from inside the plumbing of the planet

could be to the rest of humanity.

I can see the influences of what

we're doing on the surface of the Earth.

We're in the middle of Mexico

in an area where people are having trouble

finding clean water to drink,

and yet they're living on top

of a prolific water source

that if they just knew exactly

how to access it,

it could change their lives.

If I can help people

not just understand where their water is,

but how they are affecting it,

then maybe we have a chance

at solving some of these issues

like water scarcity

and global climate change.

[regulator hissing]

By the time we wrapped the expedition,

we pulled together all the maps

and discovered

that we had mapped 56 kilometers

of new passageways

and found the world's longest cave system.

That was incredible to me.

I was on cloud nine.

And it was like the possibilities

were now open to me.

We started to think

about how to make a better map.

And that's when Bill Stone

proposed our next great challenge.

He wanted to bring together

an international expedition

and make the world's first

accurate three-dimensional map

of any subterranean space, dry or wet.

And it seemed like

a bit of a crazy proposal at first,

but I thought, "I am in."

So from that point forward,

we started putting all of our efforts

into planning for this project

called the Wakulla 2 Project.

If you had asked

any respectable exploring cave diver

in the United States in those days

about what would be the greatest spring

and the greatest challenge in cave diving,

they would've instantly said

Wakulla Springs.

[dramatic music playing]

Everybody knew it. It was just gigantic,

in those days, air clear.

The sand funnel alone coming in

from this 100-meter diameter basin

was pristine white sand

kept clean by this aquifer.

It was like going to another planet.

[Heinerth] Wakulla Springs is very deep,

and it gets deep fast.

So the first thing you do

is you get down to that maximum depth,

and that's about as high

as the Statue of Liberty, 90 meters.

But then we're going

in this overhead environment

where you cannot come up.

There's no way out.

You're going in over three kilometers.

But even when you're

out to the doorway of the cave,

you've still got 17 hours

of decompression ahead of you

before you're back safely on the surface.

It would take thousands of scuba tanks

to do the dives that we did at Wakulla.

We need a completely different technology

called a rebreather.

[Stone] A rebreather

is a self-contained diving backpack

that recycles your exhaled breath.

It pulls out the carbon dioxide

that you create, it adds oxygen,

and allows you to just keep recycling

quietly for a very long time.

You can end up with between 100

and 200 times the efficiency

in terms of your dive capability

over the old traditional scuba.

[Heinerth] Basically,

you're asking a diver

to manipulate

their life support environment.

And that could be

one of the most dangerous things

they've ever done.

Too much oxygen,

and you can have a seizure.

Too little oxygen, and you can pass out.

The wrong gas choices

can cost you your life.

And there's a lot that can go wrong

with a complex piece

of electronic equipment

when you submerge it underwater.

But I was so excited

by this new technology

and what it could enable me

to do as an explorer.

I could go further or deeper

than I'd ever been before.

And that's the beauty of that gear.

The most important part

of the Wakulla project to me

was the fact

that the perception of cave divers

was changing because of this project.

For the first time in history,

we could show people exactly

where water lay beneath their feet,

and how they could be affecting the health

of that water supply beneath their feet.

Cave divers were now respected

as valued citizen scientists.

[Kakuk] One of the things that we did

at Wakulla was we were trying to condense

what other teams had done over 10 years

into a three-month period

with an international group

who hadn't dived together before.

So that's a huge undertaking.

And so trying to get people

to jell as a team

who have completely different disciplines

because of the environments they dive in,

that's a really tough, tough thing to do.

People didn't just go into the cave

with all that gear.

This massive support team of 160 people

would line up behind two people,

and those guys, they were astronauts

as far as I'm concerned.

You know,

when you saw the kit-up procedure,

there were two people per person

helping these people get all their gear on

because you can't do it yourself.

It's just too much stuff.

[Kakuk] I looked like a giant rebreather

with two little legs sticking out.

You can't even see my head behind it.

Uh, it was not fun to dive.

It's serious back aches,

things like that.

And we didn't have the timeline

to get it dialed in

as well as we could have.

[breathing heavily]

[pensive music playing]

[Heinerth] To me,

the entire project felt like a moonshot.

Everything about that project,

from the life support

to the mapping device

to the way that we handled

the decompression,

was all sort of borrowed

from concepts in space.

In fact, at one point,

Bill even reached out to NASA astronauts,

and their remark was,

"What you guys do is way more dangerous

than what we ever did as astronauts

because we had mission control.

You leave that entrance of the cave

and you go inside, and you're on your own.

That's way harder."

[dramatic music playing]

When we got past that point

of the previous world record,

we tied on a guideline

and we broke into new exploration,

and we kept on going.

And that was a huge victory for me,

but it was also a world record

for any woman going deeper

and further into a cave in history.

I realized I was on the cutting edge.

I was there. I was doing it.

And I had realized

my goals of being an explorer.

[Stone] Nobody had ever worked

in that regime underwater,

and so Jill was one of those pioneers.

It was evident that she was the lead.

She was the only female on that dive team,

and she led

the whole exploration of B Tunnel,

which was arguably the most difficult

of all the options that we had looked at.

Um, you know, so she really rose,

in my opinion,

to superstar status on that project.

[pensive music playing]

We produced a 3D map of Wakulla Springs.

We mapped 32 kilometers of tunnels.

Highly accurate, highly detailed.

You could see the features

of the cave going through

in a way that you never could

if you were doing it on a dive

because you simply couldn't see it.

[Heinerth] I think when I started

down the road of the Wakulla project,

I wasn't as confident in myself,

in my abilities.

I learned a lot over those years

just preparing for the project.

But by the time I left that project,

I felt like I had leadership

and confidence to move forward

and take on the next challenging task.

[McClellan] Jill has, like,

7500 logged dives.

Well, you know, that 7501

might be the one

where, you know, a 25-cent O-ring fails

and she's too far back,

or a rebreather fails.

I liken it to maybe someone who's married

to a police officer or a firefighter.

You know, they go off to their job,

and it's inherently dangerous.

It's inherently-- It has some risks.

But I also know that Jill

does everything she can

to minimize those risks,

and she's very clear

about communicating that to me.

And that just kind of, you know, takes

a little bit of the edge off for me.

But yeah, I worry. I do worry.

I'm sure that what I do

contributes to anxiety

and difficulty for him,

and that's hard.

But I also know

that if I quit doing what I love,

then I'm not gonna be

the woman that he fell in love with.

So there's this weird, delicate dance

that we play,

and there are times when it gets acute.

I would say that cave diving

is probably more dangerous

than what I was doing in the military.

I mean, I was deployed overseas.

I was involved in skirmishes

and things like that.

I know which end of the r*fle

the round comes out of.

But I did not go to as many memorials

or funerals in 15 years in the military

as I did in my first few years

of being married to Jill.

[somber music playing]

There are very few divers in the world

that are as experienced as Jill.

But sometimes she dives with scientists

and other people who--

Diving is just sort of a side thing

that they have to do.

And, you know, one of the rules in diving

is you have to be able to save yourself,

but you also have to be able

to rescue your buddy.

So I'm often very concerned

about who that buddy is.

Like, is that person gonna be capable

of bringing Jill out of a cave?

[pensive music playing]

[regulator hissing]

[Heinerth]

I was working with a young scientist

who needed to get

a critical bacterial sample

from inside a kind of gnarly, small cave.

And I had done plenty of dives

in this cave, and she hadn't.

In fact, we hadn't even

dived together before.

More often than not,

I work with different scientists,

extending the eyes and hands

into this remote environment.

[tense music playing]

[regulator hissing]

These aren't necessarily linear passages

where you go in and you come out.

It's like swimming

into the branches of a braided tree,

and then you have

to find your way back out.

In cave diving,

we always have a guideline,

which is a thin, usually nylon line

that we place in the cave like a pathway.

It is vital to our safety

because it's a visual reference

to the exit.

[regulator hissing]

[Heinerth] When I called the dive,

when she had the samples that she needed,

and she turned to leave...

she got stuck.

[suspenseful music playing]

And I realized that she was panicking.

All of a sudden, her fins were kicking,

and in this narrow space,

what that meant was a complete silt-out.

I grabbed onto her with one hand

and onto the guideline

with the other hand,

and I felt her wriggling

and fighting against being stuck.

[woman grunts]

[music intensifies]

[grunting]

And I'm holding onto the guideline

and holding onto her,

and they're separating

and getting farther and farther apart,

and then suddenly, the guideline breaks,

and I'm holding the bitter end

of our safety line in my hand.

The part that leads me

out of the cave is gone, and I can't see.

[tense music playing]

And for a moment, my heart was racing,

my respirations were going up,

and I'm thinking these crazy thoughts.

And at some point, I lost track of her.

I didn't know whether she'd left the cave,

whether she'd gone further into the cave.

I had no idea.

[suspenseful music playing]

And I got out my safety spool

and tied in to the bitter end of that line

to begin searching

for the other end that I could tie into.

And I realized

I couldn't just run out of the cave.

I needed to go further in.

When we pass through a cave,

even with perfect technique,

we'll disturb the visibility a little bit.

But when you reach that clear water,

you know nobody's been there.

[tense music playing]

So once I went further into the cave,

and I confirmed that she hadn't passed me

and kept on going,

then I could work my way slowly out

and, like, clear the cave, basically.

Search every corner and every side passage

to ensure I wasn't leaving her behind.

[regulator hissing]

And then my regulator packed it in.

With all the digging

and moving and patching guideline,

it was so packed with clay

that the valve was basically jammed open,

and the only way I could access

that gas supply is to turn the tank on,

take a breath, and turn it off.

[regulator clicking]

So I searched and found a side passage

where all of her scientific gear

was laying on the floor of the cave.

When cave divers panic

and the end is near,

a lot of people start shedding equipment,

tearing their mask off,

throwing down any extras,

sprinting for the exit.

And I was fairly certain

that I would find her next.

[suspenseful music playing]

And when I finally reached the exit...

there she was in the doorway.

She had surfaced and done the right thing.

She had called 911.

She had called the cave rescue team

to come out

and gone back in the water to wait for me.

But when I came out of that cave,

it was 73 minutes after her.

After an experience like that,

people tell you all the things

they wish they had said

if they wouldn't have had

the chance to say them.

They write you e-mails and notes,

and I recognized

that I was reading my own eulogy.

That's pretty hard to take,

for me, for her, and for Robert.

I think what really hit me

was when she told me

that sort of the SOS went out,

and all these cave divers

and rescue people

were on their way to rescue her, or--

I know what cave diving's about,

so they weren't gonna rescue her.

They were just gonna bring her body back.

[somber music playing]

That was the first time

in our relationship

that I really thought to myself,

"What am I gonna do

without Jill in my life?"

I mean, we had just created

this great life for ourselves,

and I don't know what I would do

if that piece was missing.

So I became very resentful

towards the whole idea of cave diving.

I don't think I became resentful

to her personally,

but just the whole idea.

And yeah, there were tears

at our house that night, me and her.

We had a real heart-to-heart,

and she explained to me

how she needed to do this.

You know, it would--

This may be just-- This may seem trivial,

but it would be like asking Tiger Woods

to stop golfing, you know?

That's not gonna happen.

But this was

more than just a sport to her.

This was a calling.

How do you keep engaging in a sport,

an activity where your friends go to die?

[pensive music playing]

I've been to so many funerals

and written quite a number

of eulogies over the years.

And I'm sure some people wonder

how I could ever go back to a place

where a friend of mine died,

or where I even brought a body

out of the cave.

Technical diving means

that a lot of people have rebreathers

and stage bottles and high-speed scooters

that take them kilometers

to faraway places that would have been

world records a decade ago.

It's not the gear that kills people,

it's people that get themselves k*lled

by the decisions they make

before they go in the water.

I have to look at risk every day

and ask myself, "Is it worth it?"

I could lose my life doing this.

[regulator hissing]

The point in my life that truly shattered

my sense of invincibility

happened in 2000

when I was exploring a place

called The Pit in the Yucatan Peninsula.

[tense music playing]

A few years earlier, Paul and I had found

these deep tunnels

that were connected to

this giant cenote sinkhole.

The Pit was unique because of the depth.

In fact, it's as deep as

the Great Pyramid is tall.

All the caves in the Yucatan

were far less than 100 meters deep.

So this could be a whole new

level of exploration.

And it might even attach

the two longest caves in the world.

At the time, I had thousands of log dives

under my belt,

and I had just been inducted

into the Women Divers Hall of Fame.

And that was a big deal for me.

So I headed off with a great deal

of confidence on that expedition.

At the time Jill was exploring in The Pit,

it was an entirely different world.

Everything was really remote.

Divers had to hike way back

out into the forest

to even access the dive site.

So there's a lot of risks involved

in doing this type of dive

because if something goes wrong,

you don't have a fast and easy

support network.

This is a dive that at the time

probably not a lot of people

were really qualified to do.

[ominous music playing]

[tense music playing]

[Heinerth] When you first put your face in

and you look down,

it's like you're in

a giant witch's cauldron.

Deep below you is this hazy, foggy layer

with tree branches sticking up out of it.

And that layer is caused

by rotting vegetation,

causing a chemical

called hydrogen sulfide.

When you actually descend

through the hydrogen sulfide,

all of your senses are just assaulted

with this rotten egg smell

that somehow gets past your scuba mask,

and even makes your eyes tear up.

But it was below the hydrogen sulfide,

deep into this witch's cauldron,

where the magic was.

[foreboding music playing]

There was nothing like this

in the Yucatan,

and we knew that we had found

something pretty remarkable.

I'll admit, it's a complete rush

when you are breaking into the unknown

and exploring a place

that nobody's ever been before.

It's enticing,

and there's definitely something

that's always drawing you forward.

[regulator hissing]

We'd made it to 120 meters, and we were

at the back of a really large room.

But ahead of us was a small restriction.

Now, continuing on

might have netted a connection

to bring together the two longest

cave systems in the world.

But we were really deep,

and we'd been down for an hour,

so I knew it was time to turn around.

Every minute longer that we stayed there

was gonna start to net a lot more

decompression and a lot more risk.

[Gibb] So the deeper you go

and the longer you stand in water,

the more nitrogen you get

into your system.

You can't go straight up to the surface

without having that nitrogen form bubbles

in your system.

This can be avoided through

a series of stops as we ascend.

That will reduce the chances

of decompression sickness.

However, there is no way to guarantee

that a diver will 100 percent

not get bent on a dive.

[ominous music playing]

[music intensifies]

[Heinerth] Where we had to decompress

was a massive opening,

you know, the size of a football stadium.

When I got to the point

about 20 meters deep,

hours into the dive,

I felt something odd happening.

[tense music playing]

The first symptom

was this sense of impending doom.

I knew something was very wrong.

I sensed this odd sensation

in my thighs first.

It felt like there were ants crawling

all over my legs inside my suit.

And then it dawned on me.

It's not bugs.

This is decompression sickness.

I'm bent. Those were bubbles.

Absolute bubbles inside my body,

ripping apart tissues, causing pain.

I knew I needed to stay underwater

as long as possible

to let the effects of the pressure

maybe push those back into my body.

But it was already too late.

I started to feel pain from my neck

to my wrists to my ankles.

I was hurting, aching everywhere.

[breathing rapidly]

Paul was actually swimming laps

around the sinkhole at this point

because he was cold.

I expected him to sort of step in

and take over,

but I think he felt powerless to help me.

I felt so alone.

This expl*si*n of thoughts

were just competing in my head.

What's happening? Am I going to get worse?

Am I going to be paralyzed?

Am I gonna die?

What about my career?

I don't know what to do.

It was so confusing and the anxiety

was just, like, filling my brain.

[disembodied voices] You're gonna die.

Your career's over. You f*cked up.

You aren't good enough. You should quit.

You'll be left in the dive shop.

What are you going to do now?

People will think you screwed up.

What the f*ck were you thinking?

You've wasted your life.

Your career's over. Stay out of it.

[suspenseful music playing]

[music intensifies]

[Heinerth] By the time I got

to the surface of the water, I thought,

"Oof, I'll just take off my gear,

and I'll climb the ladder,

and everything's gonna be okay."

But it wasn't.

With every rung of that ladder,

my body felt heavier, I felt more pain,

and the whole emotional sensation

of what was going on

was just starting to come to light.

By the time I got to the top,

I literally just rolled off into the dirt

and crawled over into the jungle

just to lay down on my sleeping mat.

But as I looked down at my biceps

and my thighs, they were swollen.

I mean, like, I looked like Popeye

swollen in my biceps,

and there were these, like,

weird, mottled,

like, ribbons of bruising

turning up on all over my body.

It was really, really scary.

[tense music playing]

What would this mean?

Would I recover from this?

Was this the end of my career?

And eventually,

I laid there and I thought,

I can't walk out of the jungle right now.

I'm gonna have to treat myself here.

So, the next morning,

I spent hours in the water,

breathing pure oxygen,

down to about 15 meters,

which, in a normal situation,

could throw someone into a seizure.

But I knew that was the best medicine

for what had happened to me.

By the time I got to the surface

of the water,

I called out to the highway

to the dive shop that was helping us out.

People hiked in and walked me out.

I was in agony and exhausted.

I could barely walk 10 steps

to just collapse and lie down.

When I finally got to Playa del Carmen

to get treatment,

what I needed was time

in a recompression chamber.

So a recompression chamber

is usually at a hospital facility.

Basically, it's a room

that can be pressurized.

The patient gets put inside the chamber,

the doors close behind them,

and then the environment inside there

is pressurized with air.

And once they're at that pressure,

then we give them 100 percent oxygen

to breathe.

And oxygen under pressure at those depths

has a couple

of really important mechanisms.

The first is just to provide oxygen

into the patient's body

to help flush out the inert gas,

the nitrogen.

There's a second

and equally important effect is that

oxygen under high pressure like that

is actually an anti-inflammatory.

It has an effect almost like steroids

to quell the body's inflammatory response

to this attack by the bubbles.

-[ominous music playing]

-[machine hissing]

There was a whole week of treatments

and consulting with the doctor.

And at the end of that week,

he only had three words for me.

And they're the worst three words

I've ever heard.

"Never dive again."

[somber music playing]

When I was told "never dive again,"

my heart sank.

I don't even know what my identity was,

how I would move forward in my

friendships, relationships, career.

So much was tied to that.

The impact of being told by a doctor

in Mexico that you'll never dive again.

I mean, that is massive

for someone like Jill.

It would be massive

if that happened to me.

You know, you're suddenly facing

an existential crisis, really.

You know, your whole life

has been torn in half

by telling you that you can't do

the one thing that defines you

and makes you happy

and gives you an income as well.

So, you know, that's a really,

that's a big moment for her.

[Heinerth] After getting bent,

that caused me to reflect on

whether I really wanted

to do this anymore.

I realized that there wasn't

a single scenario

that I could look at for a

quote-unquote "normal life"

that was gonna satisfy me.

I couldn't envision a life without diving.

And it made me reflect on what were

my motivations in the beginning.

When I graduated from university, I went

right into working in graphic design.

That meant at times that I'm sitting at my

drafting table trying to meet a deadline,

and I don't leave the office

for three days

over the Christmas holidays.

I'm there all night working,

and I'm never leaving work.

And in my mind, I'm going like, "You're

gonna k*ll yourself by the time you're 30

if you keep up this pace."

I was teaching scuba, but it was a hobby.

It was what I did on nights and weekends.

I was constantly daydreaming about diving

and envisioning that turquoise beauty.

And in the long Canadian winter,

that's what my mind and my soul needed.

[pensive music playing]

[tense music playing]

With every day that passed,

that office felt smaller,

and the walls were closing in

and the ceiling's descending on me,

until the point where I felt trapped.

That's claustrophobia for me.

But I have to say, it's those societal

pressures and familial pressures

were the hardest to navigate

as a young woman.

"What are you doing?

You're gonna be a scuba diver?

You're doing what?

You're throwing it all away?

How do you make money?

Your biological clock is ticking.

You gotta move on. You gotta get married.

You gotta settle down.

It's time to stop this childish,

playful stuff."

[dramatic music playing]

I got to the point

where it was clear to me

I could not go on living the way

I was doing,

working the way I was working.

I needed to be my own full authentic self.

When I moved to the Cayman Islands,

I did some of my first real cave dives

and my first real cave exploration.

[regulator hissing]

[pensive music playing]

Every day was just an opportunity

to go around the next corner.

To get a little bit further away

from the entrance.

To see that next thing.

And that newness, the freshness

was just so invigorating to me.

I learned a lot about the psychological

development of a cave diver

and how fear

is an important part of what I do.

But I realized that fear and facing it

is something I learned about

before I even started cave diving.

In my third year of university,

four other women and I found a house

in the Lawrence West neighborhood

in Toronto

that we could rent for the school year,

and we'd each take a bedroom.

And the first night I slept in that house,

I slept there alone.

And in the middle of the night,

I heard something.

[glass breaking]

[tense music playing]

And then I realized, "Oh, my God,

there's a burglar in my house.

If I just hide here, he won't notice me."

Downstairs, I could hear footsteps.

-I could hear drawers opening.

-[drawer opens]

-I heard his feet start up the stairs.

-[footsteps approaching]

And I thought, "How can I get help?"

I don't have a phone.

And that's when I knew

that I needed to find a weapon.

I was gonna have to defend myself.

And click, I would see a minute pass,

and then I would hear him

coming up the stairs again.

[footsteps approaching]

And he came closer.

And he came closer.

[footsteps continue approaching]

And it felt like an eternity

waiting for that door to open.

[panting]

And then suddenly, it's like an eruption.

Vroom! The door flew open.

He almost ripped it out.

And then he came after me.

And in that moment,

it's k*ll or be k*lled.

I thought he was going to r*pe me

or k*ll me or--

I didn't know what was gonna happen

but I just knew

that something awful was gonna happen

and I needed to find

every bit of strength that I had.

And as terrified as I was,

and shaking and barely able

to contain myself,

I reached out, and I slashed

with the knife across his chest

and ripped his shirt open

and tore into his flesh.

And I watched the blood

soak through his shirt.

I was staring into the face of impossible.

I don't know how I'm going

to get through this.

[panting]

It took me so long to process

what had happened.

And at first, it was just

all the victimization

and the terror and just the violation

of somebody in my space

and coming after me like that.

I would wake up in the middle of night

in a cold sweat,

and I was already fighting

that burglar in my dreams.

I remember sitting with Kim, my roommate,

and I was probably complaining

and telling her the same story

that she'd heard over and over

and over again.

I was processing these feelings

with someone

who I really respected

and cared deeply about,

and then she turned to me and said,

"When are you gonna get over this?

What are you gonna do about it?"

And I thought, "What?"

Like, where are the hugs and love?

And I guess for her, you know,

it was time for tough love.

It was time to shake me out of it.

If I couldn't get past

that moment in my life,

it was gonna define everything

moving forward.

And I needed to find something

in that experience

that I could use

that would help me to grow.

Without that near-death experience,

I may well have not dealt with

some of my other near-death experiences

in cave diving as well.

It definitely defined

the direction of my life.

[pensive music playing]

It definitely gave me the courage

to move forward and do things

that I thought were impossible.

After getting bent, my doctor told me

he knew I was gonna start to tread back

into that water one step at a time

to decide whether I was

gonna be diving again.

Ultimately, as the symptoms faded

and my confidence started to return,

I knew that I was going back to diving.

But it was gonna be a slow progression.

It was like dipping the toe in the water.

My first swim gave me anxiety.

My first dive I did on 100 percent oxygen

because there's no way you can get bent

on 100 percent oxygen in shallow water.

It was a slow progression,

a transition back to doing what I loved.

And I suppose as I started

to feel a little bit better

and my energy was restored,

so was my defiance and my stubbornness.

And there was this little voice growing

in the back of my head, "Just watch me."

I was working on television projects

with Wes Skiles

when we both decided

we wanted to do a full-length feature,

a documentary film.

The work that I do

in communicating about how

cave divers can be citizen scientists

and contribute to a better understanding

of the world,

I got that from Wes.

When he started cave diving, it was with

the intention to take pictures underwater.

He really set the whole genre

into motion and inspired a lot of people.

Both Wes and I

really wanted to go to Antarctica.

[pensive music playing]

I just wanted the experience

of going to this part of the planet

that I'd never seen before.

And when you grow up in Canada,

you're interested in the polar regions.

And at first, we thought,

"Well, maybe we'll follow in the historic

path of Ernest Shackleton."

But we were also watching

these satellite images

because these cracks were developing

in the Ross Ice Shelf down in Antarctica,

and scientists were kind of interested

in what was happening.

When the B-15 iceberg

calved away from Antarctica

and I realized there was actually

more of a story,

that was a big draw for me.

And we pitched to National Geographic

that we were gonna go to Antarctica

and be the first people to ever go

cave diving inside an iceberg.

But not just any iceberg.

The largest moving object on our planet.

The biggest iceberg to ever calve away

from the Ross Ice Shelf in Antarctica.

To get up there in front of this moving

iceberg the size of Connecticut

and say, "We're gonna go under there

and see what there is."

I mean, that even in and of itself,

you're talking about water

that's minus 3C,

you know, probably around

27 degrees Fahrenheit.

And you go down there,

and even with the best dry suit,

within 40 minutes,

your hands are becoming dysfunctional.

You know, and these guys were going

for way longer than that.

[dramatic music playing]

[Heinerth]

Most tourists that go to Antarctica today,

they have about 24 hours

of uncomfortable seas

going from South America

to the Antarctic Peninsula.

But where we were going,

we left from New Zealand

and made a 12-day crossing

of the most violent seas on the planet.

We had 20-meter waves.

We had the boat icing so heavily

that it was starting to list.

We had to get out on deck

and smash the ice off the boat

with baseball bats and hammers.

And I was seasick.

I was seasick for 12 days.

Even going to the bathroom was dangerous.

The wave hit the boat and I was literally

launched out of that tub,

against the wall,

and cut and bruised and damaged.

So, I didn't even know

if we were gonna get there.

[tense music playing]

After 12 days of t*rture,

we finally made it to Antarctica.

It was like I'd landed on another planet.

Diving in Antarctica

and going inside an iceberg,

I would say that that's definitely

the most challenging dive of my life.

There's so many risks that we faced.

I mean, the wildlife itself,

leopard seals or orcas,

there are so many uncertainties there.

The cold water,

it's as cold as it can possibly be.

There's nobody to call

for help down there.

We don't have a recompression chamber,

so if somebody gets bent,

there's no way to treat them.

The US Coast Guard actually told us

we were on our own.

About a month into our time in Antarctica,

Paul and I finally found

what we thought was the cave

that would let us deliver what we had

promised to National Geographic.

[pensive music playing]

We got to a place where we could swim

underneath the iceberg.

And the seafloor's on the bottom,

and there's this arch of ice over my head.

And it was beautiful.

There was a carpet of life

all over the seafloor,

just voraciously feeding in the current.

Meanwhile, I'm hearing creaks and cracks

and thuds and retorts

and all kinds of sounds

that I could not only hear,

but I could feel them in the sternum,

in my chest.

Paul and I, at one point, had returned

to where we'd gone into the iceberg,

and the doorway was blocked

with broken ice.

So, Paul and I just start swimming

around and under all these blocks,

and some of them

are sort of moving and shifting.

And when I finally swam through

these chunks and I got to the surface,

Wes is hanging over the boat

and his face was so animated.

And he's like, "What happened?

We thought you were dead.

When the ice wall just sort of broke away,

it created this huge wave

and it almost threw us out of the boat.

And then we realized where you

had gone in, it was blocked."

We had no idea the stress

that everybody topside had experienced.

[tense music playing]

I often look at expeditions,

and I realize there's a mounting pressure

that happens as the project moves on.

You start taking risks,

and it's to get the goods,

it's to get the job done.

It's because of the pressures

from everybody around you.

Wes hadn't even been inside the cave yet.

And we needed to show it to him,

to photograph what we needed

for our movie.

[pensive music playing]

We descended down that crack

and went underneath the iceberg.

We were filming all these beautiful

filter-feeding organisms,

and the dive was going perfectly well.

And then I felt the current picking up,

and getting faster and faster,

and it had literally turned now,

and it was sweeping us into the iceberg.

-And I thought, "Ooh, this is bad."

-[suspenseful music playing]

But simultaneously,

I also had a leak in my glove,

and my hand was soaking wet.

And I had put up with that

as long as I possibly could.

Between the current

and the pain in my hand,

I turned to the guys

and I called the dive.

It's time to go.

We turned around to try and escape

through this tunnel.

The current was getting too strong.

We dug our hands

into this doughy seafloor,

like throwing up these wispy silk piles

and displacing these animals

as we tried to pull ourselves along.

I'm fighting for my life,

and I hear Wes yell,

"Help me with the camera!"

I'm like, "Are you kidding me?

f*ck the camera.

We've got to get out of here."

I was doing everything I could to survive

at that point,

and I was leading the other two

out of the cave.

Well, Paul drifted back to help Wes,

and I'm thinking, "I'm pissed.

Equipment is not worth it.

Let's get out of here."

[music intensifies]

Finally we get to the point

where we're at the bottom of this crevice,

and we need to go up.

But the current is pressing me down

and back into the cave.

And I suddenly realized that these

little ice fish I'd been observing

had created burrows in the ice,

and I might be able to use those burrows

to stick my fingers in

and climb the ice wall.

And I thought,

"Uh-huh, you guys are pretty cool,

but I need those holes."

And I started using my finger

and pressing them into the holes

of the ice-fish burrows,

and using those like a climber

would to climb the ice wall.

And Wes and Paul copied and followed,

and we finally got up to the point

where we now had a decompression

obligation over our heads,

and we had to stay

in this freezing cold water,

turning a one-hour dive

into a three-hour ordeal.

[dramatic music playing]

When I finally swam back to that boat,

I remember the chief scientist

looking down on me.

And I'm holding on to the ladder and I'm

looking up at Greg on the boat and I said,

"The cave tried to keep us today."

And it was true.

I think that's as close

as I've ever felt to death.

We put our gear aside

and went to have dinner.

And then I heard screams on the deck.

I thought, "What's going on?"

And we ran up on deck

and Wes grabbed the camera,

and I couldn't believe what I was seeing.

[dramatic music playing]

That cave I'd just been inside of

and just narrowly escaped was no more.

[tense music playing]

After seeing that whole iceberg collapse,

and really even after just

going to Antarctica,

I felt so small,

but I also felt the majesty and wonder

of Mother Nature

and the fragility.

And I wanted to communicate to people

about climate change

and water issues and beauty and wonder.

And when I shared my adventures,

I was gonna shove a little truth

in there too.

And hopefully teach people about

how magical this planet is,

and how we can protect it

if we all take care of our square foot

and make good choices

about the next step forward.

I still ask myself this whole question

about what is my legacy.

What am I doing?

Why am I doing this?

And today, I think my ultimate goal is

to be the woman that I wish I had met

when I was 10 years old.

[indistinct chatter]

[pensive music playing]

It's been my greatest honor

to come home and resettle myself

back in Canada,

and go into the school system and talk

to kids about exploration and discovery.

Education and outreach

are critical to what I do

and it gives me a sense of purpose.

I really hope that my work will inspire

young girls to know

that anything is possible,

anything they want to do,

despite the social, cultural,

or familial barriers

that they might be facing.

Anything is possible

when we put our minds to it.

If I can give people hope and optimism,

I will have done my job.

[dramatic music playing]

I've never lost sight

of wanting to be an astronaut.

It's been really exciting for me

to work with technologies underwater

that are now destined for space.

[dramatic music playing]

I'll be diving in one way or another

for the rest of my life.

I feel like an earthbound astronaut.

I want people

to really think about fear

and how that directs our lives,

how it can stifle us,

and how we can miss out.

[music intensifies]

If we don't face it and embrace it,

we're gonna run from it

for our whole lives.

Without exploration and discovery,

we are dead.

We will not progress as a society.

So the only answer is to face it...

and step into it.

Face the fear.

Step into the darkness.

Let your eyes adjust,

and then do something new

for yourself and for humanity.

[pensive music playing]

[regulator hissing]

[regulator hissing]

[pensive music playing]