07x13 - Jonathan Bird's Blue World

[bunniefuu]

[bright music]

- [Narrator] Today on "Blue World,"

Jonathan explores the longest
submerged cave in the world.

But first, the whole family
dives a wreck of Grand Cayman.

[excited music]

Meet Jonathan Bird,

one of the world's top underwater
nature cinematographers,

traveling the world on assignment

for all the major networks.

He is an Emmy Award-winning authority

on the underwater world.

In freshwater or salt,
reefs, wrecks, or caves,

Jonathan documents the
world beneath the waves.

Welcome to the "Blue World."

[bright music]

- [Jonathan] It's Spring
Break so the family and I

are heading out on a dive adventure.

We take off from gloomy Boston

and land in beautiful Grand Cayman.

[lively music]

We're staying at Sunset House,

one of the premier dive
resorts on an island known

around the world for its fabulous diving.

Grand Cayman is located in
the Caribbean, south of Cuba.

The family and I have
had some fabulous dives.

We've seen lots of marine life,

[gentle music]

healthy reefs,

and of course, we've
played with stingrays.

[gentle music]

But today, we're heading
out on another adventure.

Jasmine and Phil ready the
boat for a special dive

we've been looking forward to doing.

It's a short boat ride to the site,

but we have time to set
up our gear and get ready.

- [Jasmine] Yeah, here you go.

Take a look at this hold so I can hold it.

It's gonna hurt.

- [Jonathan] Phil gives us a briefing

for our dive on the
wreck of the Kittiwake.

- 1.6 feet long.

It was born in-

- [Jonathan] The USS
Kittiwake was a 251-foot long

submarine rescue vessel, which served

for 50 years in the U.S. Navy.

Eventually being decommissioned in 1994.

In 2011, it was intentionally sunk

as an artificial reef on Grand Cayman.

If the Kittiwake sounds familiar,

it may be because of this guy.

Hey, Jake.

- Hi.

- [Jonathan] How you doing, man?

Eight years ago,

we got a young fan named
Jake scuba certified

and took him to Grand
Cayman on an adventure.

The first dive we did together

after he got his certification
was the Kittiwake.

At the time, it was a brand new wreck

having been sunk only months before.

Eight years later, things have changed.

Originally, it was nearly upright,

but after eight years of storms,

the wreck has tipped on its side.

The family and I sink down

and start exploring at the stern,

checking out the giant propeller.

Back when Jake and I dove here,

the prop was completely out of the sand.

But now the ship has settled
so much that one blade

of the prop is completely buried.

[gentle music]

We swim up and over the
wreck and into the ship.

[gentle music]

Because there are so many openings,

you're never out of sight of an exit.

So this is completely safe for
experienced divers like us.

Because the ship is tilted on its side,

it gives divers a weird vertigo.

My brain has a hard time
interpreting which way is up,

but Elise's bubbles go straight up.

[gentle music]

In the engine room,

we can find one of the V12 engine blocks

that once powered the ship.

[calm music]

Eventually, Liam leads the way up

through the smokestack back into the blue.

[gentle music]

Back when Jake and I dove the Kittiwake,

the wreck was so new

that there was barely any marine growth.

But now, the ship is covered in red

and crusting sponges, coral, and algae.

[calm music]

Jake had a great time playing
with the wheel on the bridge

as if he was driving the ship.

Now the wheel's covered
in growth that Elise

doesn't want to touch.

[mysterious music]

And the bridge itself has
been torn off by storms.

Liam isn't afraid of the marine growth.

[playful music]

We follow Jasmine

and she points out the
water cannon, which was used

for fighting fires on other boats.

It has some stinging hydroids on it,

so Liam isn't sure he wants to touch it.

[calm music]

Elise takes a break on the cargo boom

'cause diving is really tiring
and there's a great view,

but Christine found something

you don't normally see on a wreck.

A grouper is actually
visiting a cleaning station

behind a ladder.

[gentle music]

It takes him a while to
get used to my presence,

but once he decides I'm not
a threat, he opens his mouth

to allow tiny cleaner
gobies to clean his teeth.

[gentle music]

It's an unspoken rule of the sea.

Nobody eats the cleaner fish.

[gentle music]

Eventually, the cleaning is over

and the grouper heads out.

We take a cue from the fish
and head back to the surface.

- That dive was amazing.

The ship on its side makes
everything so much cooler.

- Man, the wreck is so
much more interesting

than it was in 2009.

Not only is the tilt just really spooky

and cool, but just the whole atmosphere

of the wreck has gotten much more,

I can't really describe it.

Like ethereal, just swimming
through it is so much fun.

I am betting the kids had a blast.

In the eight years since
I last dove the Kittiwake,

the wreck has changed significantly.

It has tilted on its
side, sunk into the sand,

lost some of its super structure,

and grown more marine life.

But all of these changes
have only made the wreck

more interesting to dive.

It's more colorful, more fun,

and there's more to see.

Like a fine wine, wrecks
usually get better with age,

and the Kittiwake is no exception.

- [Narrator] Coming up,
Jonathan explores the Bird Cage,

a section of the longest
submerged cave in the world.

- [Jonathan] The jungle of the Yucatan

is filled with mysteries and adventure.

From miles and miles,

it's only trees with no
sign of rivers or lakes,

but there are rivers.

They flow underground
through vast cave systems.

In a few places, the ceiling
of the cave has collapsed,

creating cenotes, entrances
to the cave systems.

In one cenote called Zapote,

we explored unusual
formations called cave bells

formed by bacteria.

But the toxic hydrogen
sulfide layer prevented us

from going too deep to
explore much of the cave.

About an hour drive away from
Zapote is another cenote.

This one will allow us to really explore.

Cameraman Todd and I
are on an epic adventure

to the Yucatan of Mexico.

Of course, whenever we go
cave diving in the Yucatan,

we meet up with our good
friend, Christine Loew,

an experienced local
cave diving instructor

who knows all the good spots.

And our adventure begins
on a nice smooth dirt road

into the jungle.

[playful music]

Soon, we arrive at Cenote Nohoch.

The owners of the cenote have built a bit

of a tourist attraction around
it with an observation tower

and some zip lines.

But for us, it's all about the diving.

Nohoch Nah Chich,

which means giant bird
cage is a cave system

that stretches over 42 miles

and has 36 different
cenotes providing access.

Cenote Nohoch is right in the
center of the whole thing,

and we're definitely not going to see much

of this huge system in one dive.

- And we also gonna
dive in that direction.

- [Jonathan] Christine walks
us through the facilities,

then we review the dive plan.

- So a little Mayan lesson.

Nohoch Nah Chich means giant bird cage.

- [Jonathan] Giant bird cage?

How cool is that?

This is my place, baby.

Because there are so
many different routes,

we have to make a careful
plan on where we're going

and what is involved,

but we can't dive until
all the gear is ready.

[playful music]

This is a popular place for cave divers,

so they have a really nice setup.

[playful music]

Finally, the fun part, you
gotta get your mask just right

because once you put your helmet on,

you can't really adjust it.

Then we follow Christine down
into the crystal clear water.

[magical music]

As we prepare to leave the cavern zone

where we can see light from the sun,

Christine ties off a line.

The permanent cave lines start
a few hundred feet further

into the cave to keep open water
divers from following them.

So we start with our own line

that leads from there
back to the cavern zone.

Since every dive team
places their own line

from the main line back out of the cave,

each team always knows
when there are other divers

in the cave.

[magical music]

Reaching the main line,

Christine ties our
team's reel to the line.

Then she places a marker
called a cookie on the line.

That marker has her name on it,

so nobody else will
take it out by mistake.

[magical music]

Nohoch is known as one of
the most beautiful caves

in the Yucatan with good reason.

Everywhere we look, there
are gorgeous formations.

[magical music]

And some areas were very shallow

and the water doesn't
completely fill the cave,

so there were huge air
pockets above our heads.

In theory, you could stick
your head up in the air

and have a conversation.

However, since these air
pockets don't directly connect

to the air outside the
cave, there's no way

of knowing if the air is safe to breathe.

[magical music]

But it looks cool like
an upside down puddle

above our heads.

[magical music]

As we swim weightlessly
through these winding passages,

it's hard to believe
that 15,000 years ago,

these passages were dry.

[magical music]

Back then, during the last ice age,

sea levels were much lower,

so the water table in
the jungle was lower too.

[magical music]

These caves were bone dry.

We could have walked
through this cave back then.

[magical music]

And the evidence is here.

Formations hanging from the
ceiling called stalactites

were created by dripping water,

almost like icicles of stone.

[magical music]

When the dripping water
hit the floor of the cave,

the result was stalagmites.

And as those two formations grow,

they can meet in the
middle forming a column.

Soon, we reach our first jump.

We're going to leave the main line

and go down a side passage.

So we have to make

what is called a jump
over to another line.

The side passages already
have permanent lines in them,

but they don't connect to the main line

because that can be confusing.

So we put our own line
between them temporarily.

Christine ties a spool to the main line.

Then we swim across the jump

and tie onto the line on the side passage.

When we return, this jump line ensures

that we can find the main line again.

This is one of the unbreakable
rules of cave diving.

Never be out of sight of the line

that leads all the way to the entrance.

[gentle music]

Soon, we come into an amazing room

filled with crazy formations
known as helictites.

Helictites are thin little
whisker like formations

that go sideways off the drip formations.

Nobody's quite sure how they form.

For a long time, the prevailing theory

was that they're formed by wind,

blowing dripping water sideways.

But more recent evidence suggests

that surface tension caused

by a special kind of
bacteria may be the cause.

Either way, they grow in a dry
cave, not a submerged cave.

As we keep going, Christine leads us

through very large rooms.

The crystal clear water
flows beneath the forest,

the lifeblood of the Yucatan.

[calm music]

And most of the time we're
no deeper than 30 feet,

just above our heads, a
thick tropical jungle.

While some of the formations are opaque,

some of them allow light to pass

like a flashlight behind a finger.

[magical music]

Our goal is to leave nothing but bubbles

and pristine cave behind.

[magical music]

A beautiful flow stone formation
reminds me of a waterfall,

frozen in time, sculpted in stone.

[magical music]

A formation like this takes
thousands of years to form.

[magical music]

Finally, it's time to turn back.

Another firm rule of cave diving

is that you can only use
one third of your air

to get into the cave.

You use another third to get back.

That leaves the last third
for unexpected delays.

[magical music]

Soon, we get back to the jump

and Christine spools up her
jump line as we cross back

to the main line.

The arrows point the way out

because obviously, following
the line in the wrong direction

would be disastrous.

[magical music]

[magical music continues]

People think cave divers are nuts,

but look at the things we get to see.

[magical music]

As we swim back to the
entrance and hits a long swim,

I have time to think about
how far this cave goes.

We swam only a half a mile into a cave,

which is 42 miles long.

But a few years ago, cave
explorers linked this cave

to another huge system called Sac Actun.

Then they linked Sac Actun
to a system called Dos Ojos.

These three systems together

are now the longest
underwater cave in the world,

stretching 215 miles.

[magical music]

And with that humbling fact in mind,

finally, we make it back

to the cavern zone where we
can see the light from the sun.

[magical music]

Fortunately, we never
went deeper than 30 feet.

So even though our dive
was two hours long,

we have no decompression to do.

- Woo.

- Wow, man, that was a great-

- Stunning.

What a gorgeous environment that is.

My lower back is like on fire.

I feel incredibly lucky to
have visited Nohoch Nah Chich.

Nevermind the fact

that I can brag about diving the longest

known submerged cave in the world,

it's just a beautiful cave
with crystal clear water,

almost no current and shallow
enough to stay for hours.

Indeed, a treasure of the blue world.

[gentle music]

[excited music]

[gentle music]