Sara Campbell - Extreme Diving Super Human Challenge

In my quest to find real-life superhumans,

I've taken to the depths.

Human beings like you and me are able to explore this amazing

underwater world using breathing equipment, like this scuba gear.

But imagine being able to be down here for minutes at a time

without any breathing equipment at all.

You'd need incredible abilities underwater - huge lungs,

amazing swimming skills, fish-like streamlining.

You'd need the powers of a real-life superhero,

a superhero like Aquagirl,

perfectly at home underwater,

and with unbelievable swimming ability.

Well, I've heard of a real-life Aquagirl.

Sara Campbell is one of the world's greatest freedivers.

With just one breath, Sara can dive to crushing depths

few ordinary humans could survive.

She's broken four world records,

and won the Freediving World Championships.

Freediving is what we call diving underwater

without any special breathing equipment, for example, scuba gear.

With the right training and experience,

freedivers can dive very, very deep.

But without the right training and supervision,

it can be very, very dangerous.

Tim has travelled all the way to Dubai to meet this superhuman.

And here she is, Sara.

-How amazing to meet you, hi.

-Hi, lovely to meet you too.

Now, tell me, what is the longest you've ever held your breath?

Me personally? Just over five minutes,

which, to the average person, it sounds like a big number.

That's amazing. What is the attraction for you

of not wearing scuba gear?

The freedom of how I can move in the water, and then also the challenge.

You know, scuba is not really a sport, whereas freediving,

learning to hold your breath, pushing your body...

Every time I jump in the water, it's like I'm learning about myself

and learning really what's possible. So far, I haven't found the limit.

With scuba diving, there's a depth which you can get to, basically,

-but you're going below that, are you?

-Yes, I dive a lot deeper than

-most scuba divers.

-Wow, right, wow.

You have the most incredible abilities.

We would love to put you to the test.

We've set up three Super Tests designed to help us examine you

and to try and help us understand what makes you unique.

We've searched high and low to find somebody to measure up

against you, but we couldn't find anyone.

So I'm going to have to do. Is that OK?

-That sounds brilliant.

-OK, let's go.

-Let's go.

This is Dr Megan John. She's an expedition doctor

and has kept people alive while they attempt some of the most

dangerous activities you can imagine.

She's created three Super Tests to find out how Tim

and Sara's bodies react differently.

For Super Test One, I've brought the two of you here

to the Ambassador Lagoon, Dubai. Because here,

-they've got one of the biggest aquariums in the world.

-Wow.

In my Super Test One, you'll both be wearing scuba equipment.

I'm going to be looking at how long you can each make

the air in a tank last you.

Inside this tank, there are 60,000 fish.

Are you two ready to take the plunge and join them?

-I can't wait.

-Are there sharks?

-Wait and see.

-OK. This is brilliant!

Scuba diving is different from freediving.

Scuba divers breathe underwater using tanks full of air,

which get used up during the dive.

Sara and Tim will be using scuba tanks in Super Test One,

so Dr Megan can measure how much air they use while they swim about.

It's important they don't stop to admire the fish, though,

so Dr Megan has organised a game that they have to play.

She's hidden 20 coloured marbles in the fish tank. Sara has to find

the ten yellow ones, and Tim the ten red ones,

and they have to put them in a tray to get counted.

So, Sara, do you have any tips that might help me?

Yes, absolutely. The most important thing when you're in the water,

whether it's freediving or scuba diving, is to remain calm.

And the way that we remain calm,

the best way is to manage how we breathe.

Make sure that you keep it calm, keep it slow, relatively deep.

If you find that you're breathing very shallowly and rapidly,

that means that you're getting into a panic state and that is going to

have an effect, not only on keeping your mind nice and calm, so stopping

you getting too excited while you're looking for those marbles,

but it's also going to keep your heartrate low, which means

you're going to use less of the air in your tank as you swim around.

Oh, right, so not only does it stop me from getting panicky,

-it also helps me to save air.

-Yes.

Very clever. So long, slow, deep breaths

Yes, absolutely.

Long, slow, deep breaths? Easier said than done.

Once Sara and Tim start looking for the marbles in Super Test One,

there's a good chance they'll forget all about their breathing.

Sara, Tim. I've set you both up with tanks filled with identical

amounts of air, 200 bar. They've each got a gauge

which will start at 200,

and the needle will go down as you use up the air inside.

Don't worry, I've made sure there's more than enough in each tank

to last you both 20 minutes.

You've also got these specially adapted masks, which will

allow you to talk to me while you do the challenge.

-But I would suggest you don't talk too much.

-Cos it uses lots of air.

-Exactly.

-So, like, "Wow, a fish! Wow, a marble! Wow, a thing!

"Wow, this!" would not be good.

-There's 60,000 fish down there.

-That would take a lot of air.

-That would.

Scuba diving can be very dangerous,

and even experienced scuba divers can get into difficult situations.

Diving deeper can cause you to sink faster

and not knowing how to get back to the surface can cause you to panic.

Panic causes you to use more oxygen, meaning the air level

in your tank will start to drop faster.

If you try to swim to the surface too quickly, the change

in water pressure can cause earache and your ears could start to bleed.

You may get decompression sickness.

Decompression sickness can cause sore joints and breathing problems.

In severe cases, it can cause dizziness, confusion,

unconsciousness and death.

To make sure Sara and Tim are as safe as possible

during Super Test One, they've had training beforehand,

and a team of safety divers will be in the water with them at all times.

OK, then, guys. You get your kit on.

I'm going to head down to the observation window.

When you're ready, you head over there

and I'll give you a cue on the walkie-talkie. OK?

-Yep. Ready?

-Good luck.

-Brilliant, let's do this.

Sara doesn't normally use scuba gear.

With her freediving abilities, she doesn't need it.

But by using it today, Dr Megan can see how much air

her and Tim use during the 20-minute test.

OK, then, guys, are you ready?

Three, two, one, dive!

It's a massive tank, full of moving fish.

How on earth are they going to find any marbles?

I did notice that some of the fish have been pushing

the marbles around - that could make it even harder for them.

Sara and Tim are trying to stay relaxed

and swim as efficiently as possible in this test,

just like a freediver has to

when trying to make one breath of air last.

It's interesting, Sara's body language,

keeping her arms very still.

It'll be interesting when Tim comes back round

to see how he's managing.

Early in the test, and Tim seems to be doing quite well,

keeping relaxed while he swims around.

So they've not found any yet.

Nearly four minutes.

At the end of the 20-minute test,

Dr Megan will read the gauges in their tanks

to see how well they've managed to make their air last.

I've got one, hurray!

Oh! I've found my first one too.

There we go. Sara, the first marble in the basket.

Tim's got one too.

Just seconds apart.

This is a great way of testing how the guys use their air.

Because it's very distracting - this is a competition,

this is a game for them, so they can't think about just technique.

Yeah, that's my second.

There we go, Sara's coming in with her second now.

Ha-ha, look at that!

5 minutes and 30 seconds.

I have lost my marbles.

Number three, so three to one. Nearly seven minutes.

Remember, I'm not interested, really,

in how many marbles they get.

I'm using that as a distraction to keep them both swimming

so I can record how much air they use in the 20 minutes.

The more Tim and Sara move round, the more oxygen they'll use up.

This is because everything in your body is made up of tiny cells.

There are lots of different types of cells - skin cells,

muscle cells, nerve cells, and even bone cells.

Every single cell needs oxygen and sugars from your body

to work properly.

They use the oxygen and sugars in a chemical reaction

to make energy, and this is called respiration.

Respiration also makes water and another gas called carbon dioxide.

You don't NEED carbon dioxide, so you get rid of it when you breathe out.

The harder your cells work, the more oxygen they need

and the more oxygen you breathe in.

Sara's doing well not getting stressed out,

considering where some of the marbles have been hidden.

I've found another ball, but it's in here.

I don't know if my arms are long enough to get it.

If I were freediving now, I could get inside here easily.

But with all this breathing equipment, I can't.

Tim is struggling to keep his breathing under control.

It's really hard down here to try

and concentrate on breathing slowly. Way overexcited.

And the more excited Tim is,

the more oxygen his body will be demanding.

Oxygen gets into your body through your lungs.

Your lungs are made of lots of tubes that branch out like a tree.

At the end of the tubes are tiny air sacs called alveoli.

The average human body has 700 million alveoli,

and if they were all laid flat, they'd cover half a tennis court.

When you breathe in, air goes right down into the alveoli.

Alveoli are covered in blood vessels, and oxygen from the air goes through

the walls of the alveoli into your blood to be carried round your body.

The faster you breathe, the more

oxygen your lungs will take in from the air.

I just found two.

Sara's just showing the cameraman she's got two marbles in her hands.

I wonder if Tim noticed.

Sara's got another one there, look, I can see that.

I really have no idea where they are.

So that's five marbles to Sara, three to Tim...

..at 13 minutes and 45 seconds.

A big part of Sara's amazing ability as a freediver

is keeping calm whilst diving.

In general, watching Sara is more peaceful, she's more relaxed,

she moves a lot less and she doesn't use her arms at all.

With all his flapping about in the water,

Tim must be using more air than Sara.

As the time goes on, they both seem to be working harder.

So that's five marbles for Sara, four for Tim,

with three minutes to go.

What's really important is not how many marbles they get,

but how much air they've used by the end of the test.

Obviously, we know that Sara is much more experienced in the water

and much more comfortable in the water than Tim is.

Because of that, she's using a lot less movement,

she's more confident. And Sara's coming in with another one.

That's 20 minutes. If you can both finish now.

The two of them are heading back up to the surface.

I want to find out how much air they've both used.

With the test over, Sara's right to look happy.

I'm OK!

She collected six marbles while Tim only had five.

Fresh air!

But it's not the marbles they've collected that's important.

Good, you're out.

It's how much air they used.

And Dr Megan's looking at the results now.

Tim, during the 20 minutes, you used up 110 bar of air.

But, Sara, I'm completely blown away.

You only used 60 bars of air.

You would have been able to last almost double

the length of time that Tim did.

I know you're a bit smaller than Tim, so I might have expected him

to use a LITTLE bit more, but that difference is phenomenal.

I used up a lot of air searching for marbles,

but long ago in the Middle East, people searched the ocean floor

for a different prize, using just one breath.

For hundreds of years, diving for pearls was a popular job in Dubai.

Pearl divers would freedive up to as 40m down to the seabed

to collect oysters which make pearls.

The divers collected as many oysters in one dive as they could,

holding their breath for up to five minutes at a time.

When they ran out of air, they'd tug on a rope

and be pulled to the surface.

They dived all day, risking their lives among poisonous jellyfish

and sharks for the valuable pearls.

Freediving has always existed.

Many cultures around the world

have relied on swimming while holding their breath to find food,

long before scuba-diving equipment was ever thought of.

Most mammals can dive for brief periods under water. In fact,

some mammals went from spending a short time underwater

to living full-time there.

Sara's a world champion, and with all her training,

she can hold her breath for around five minutes underwater. Amazing.

But some mammals, like whales, can dive for 90 minutes

on just one huge breathe.

All mammals have a special trick that lets them dive

so well underwater. It's called the mammalian dive reflex,

and it starts as soon as your face hits the water.

Most people can hold their breath for a short while,

but underwater, you can hold your breath for a bit longer.

This is because nerve cells on your face send information

to your brain, telling it that you're underwater.

Your brain then sends signals round your body.

This causes less blood to flow to your arms and legs

so they use less oxygen, and your heartrate slows down.

Using less oxygen means that the air in your lungs will last longer

and this means you can hold your breath for a bit longer.

With years of training, this automatic dive reflex helps

top freedivers, but it will not save the average human from drowning

if they run out of air.

You must never fight your body's natural need to breathe.

You really could drown.

To be able to be a great freediver like Sara, you need to be able

to stay under the water for as long as possible.

To do this really well, you'll need to take as much air as possible

down with you in your lungs.

In Super Test Two, I want to look at how much air

you can hold in your lungs. I'm going to do that using a spirometer.

How does it work?

Well, I'll be asking the two of you to take a deep breathe in,

and then out and back in again though the tube.

The computer will then give me a readout about the total amount

of air you can fit into your lungs.

-Great.

-Shall we try it?

-Yeah, let's have a go.

-OK.

-Right then, Tim, you're up first.

-OK.

-When you're ready.

Tim's filling his lungs with as much air as he can.

Breathing right out...

Whoa, Tim, don't hurt yourself.

Don't forget to breathe back in again.

The machine can now measure how much his lungs can hold

compared with the average man of his size.

-Let's have a look.

-Did that work?

-You went purple.

-Did I?

-Yes.

-I tried really hard.

You might think that it's your lungs

that make you breathe in and out, but it's not.

It's done by a very clever muscle.

Your diaphragm is a stretchy muscle

that sits right underneath your lungs.

When it moves down, it pulls air into your lungs

and when it moves up, it pushes air out of your lungs.

Your brain controls your diaphragm, making it move 12 times every minute.

When you're breathing at rest, you will only fill around a quarter

of your lungs with air.

But if you pull your diaphragm as low as you can,

you can fill your lungs completely with air.

The maximum amount your lungs hold is called your lung capacity.

With training, you can make your lung capacity bigger.

-OK, Sara, you're up next. When you're ready.

-Yep.

A deep, controlled breath from Sara.

She looks like she knows what she's doing.

That's amazing, you actually become a square.

You know, like normally, you're a normal person-shape

and then suddenly you go... and you inflate yourself.

-You inflate yourself.

-I'm a pufferfish.

Now, Tim, you did better than I expected.

-10% better than average.

-OK.

-Really well done.

Thanks. That's really exciting.

Sara, however, you achieved 3.82 litres.

That's over 22% more than we would have expected for your size.

Phenomenal.

With an incredible 22% more than the average lung capacity,

Sara has a lot of breath to use during a dive.

It's no wonder she's one of the best freedivers in the world.

So, how does Sara do it?

Sara's lungs might not be bigger than the average person,

but years of training have made her diaphragm superstrong, so Sara can

stretch her lungs to make them even bigger and hold even more oxygen.

Sara uses mental exercises to keep herself calm and relaxed,

and moves as little as she can.

This slows down her heartrate and uses less oxygen.

Sara is also quite small,

and smaller bodies use less oxygen than bigger ones.

All this means that when Sara dives, not only does she hold more air

than an average person, but she uses it up more slowly.

This allows her to dive for a long, long time on just one breath.

Holding your breath's hard enough when you're relaxed.

But imagine trying to do it with a shark in the water.

On Reunion Island near Madagascar, there have been

so many shark attacks that swimming was banned.

Luckily, freediver Fred Buyle came to the rescue.

He can hold his breath calmly at the bottom of the ocean

without disturbing the sharks.

Incredibly, when Fred plays music, the sharks come to investigate.

When they get close, he puts a tracker on them

without hurting them. Now, people can swim safely

because lifeguards know exactly where the sharks are.

For the final Super Test, Dr Megan has taken Sara and Tim

off to the coast of Fujairah, in the Gulf of Oman.

Super Tests One and Two, to control the environment,

we carried them out in an aquarium.

But to really see what Sara can do with her freediving,

I've had to find somewhere a lot deeper - the ocean.

The team have come to a deep-water location

and dropped a line an incredible 50 metres down.

This line will mark the depth and keep Sara and Tim on course.

With one breath, they will attempt to swim all the way to the bottom

and return. 100 metres - that's like swimming

the length of a football pitch with one breath.

Because it's such a risky challenge that we're undertaking,

I've put together my largest ever safety team.

I've got a lot of medical experts here on standby.

We've got specialist safety scuba divers in the water

and some specialist safety freedivers.

If Sara and Tim get into trouble,

we need to get them out straight away.

The two of them could black out or sustain pressure injuries.

One factor that the team hadn't reckoned on was the bad weather.

There's a strong current today,

which is dragging the weighted safety line to one side.

This could mean that Tim and Sara get pulled away with the line

and have to waste precious air swimming against the current.

In that case, they might not make it all the way down

to the target 50 metres.

So here we are. The boats are in position.

Before I set you off, I've done a little bit of an experiment.

-Have a look at this metal bottle.

-Yeah.

See if you can crush it.

Oh, it's really strong, isn't it?

-Not really making any inroads, are you, Tim?

-No. None at all.

I sent an identical bottle down to the sort of depths

that Sara's going dive to.

Dr Megan has placed cameras on the bottle

to show what the pressure does at just 30 metres.

Oh, my word.

-And look what happened.

-Whoa!

That's the effect of the pressure down at depths, crushing in.

It's what would happen to your body if we sent you down.

The deeper you dive, the more your body gets

squashed by the pressure of water around you.

The pressure is so strong, it can burst your eardrums.

The deeper you go, the more your body gets squeezed, and soon your lungs

get squashed so they'll only be the size of oranges.

Blood and bodily fluids get pushed into your lungs

and they can start to bleed.

When you dive below ten metres, you will stop being able to float

and you'll be sucked down towards the bottom.

And if you try to come back up, the sudden change in water pressure

can make you pass out.

Then you'll run out of oxygen and die.

I'm afraid, Tim, I've got some bad news.

Because of that, the BBC safety authorities have decided

you just can't try this challenge.

Whoa, OK. I mean, Sara, it's really that dangerous?

With no training, absolutely.

There are many, many risks involved with freediving.

If you don't know what you're doing,

you should never, ever have a go on your own.

So I appreciate that possibly today is not your day.

But today might not be Sara's day, either.

Although she's dived twice as deep to over 100 metres,

setting her own personal record in the past,

the choppy sea conditions today are still a cause for concern.

It could cause her big problems in the dive.

OK, we've set the rope,

and we do have quite a bit of current today, actually.

So the rope is kind of at this angle, which isn't ideal.

It's also less than ten metres' visibility.

So these are both conditions that I'm really not used to diving in.

For Sara's dive, I'll be fitting her with this specialist dive computer.

It'll give me readouts of her heartrate

as she goes through the dive.

It'll be really interesting to see what story that tells.

Are you happy with that, guys?

Before each dive, Sara goes through a preparation routine.

She takes controlled breaths and relaxes her body, ready to begin

the attempt to make the incredible 50-metre dive in one breath.

Sara's done all her breathing exercises and warm-up,

she's ready to go. Good luck, Sara.

She's away!

For safety, Sara is tethered to the rope.

Without it, she might drift off course and get lost.

Amazing, she's like a massive big fish, isn't she? Beautiful,

stunning, willowing through the water with the big fins coming out

-behind her. It's amazing.

-She's like a beautiful silver mermaid, Tim.

As the air in her lungs is squashed, she becomes less buoyant.

If she passes out now, she'll just carry on sinking.

She's just gone past the point where she doesn't need to paddle any more,

because your body suddenly gets heavier and you get sucked down.

Sara is at the point now that the bottle crushed in the experiment.

From years of training, Sara can withstand the pressure,

being able to equalise her ears,

and her amazing diaphragm stretching to allow the shrinking of her lungs.

She just seems so very relaxed in the water. That's amazing, isn't it?

She uses a lot less oxygen so she needs a lot less air,

so she can keep going for longer.

With every metre she goes down, the pressure crushes her more.

and she has less and less oxygen left in her lungs.

So she's getting to the bottom now. She's nearly 50 metres down.

-It's incredible. 50 metres is a really long way.

-It's phenomenal.

She's reached the bottom. It's amazing!

50 metres down with just one breath of air -

and all under crushing pressure.

A normal person would be in agony as the water pressure

squeezed on their chest, and they would suffer burst eardrums.

The pressure on her body, the squeezing must be incredible.

Her heartrate's now down at 46,

that's less than half what it was at the surface.

But, unbelievably,

the most dangerous part of the test is still ahead of her.

Her body would have a huge amount of pressure on it,

squishing her lungs in, squishing in on her ears and her head.

She could start to get light-headed if she doesn't come up.

Only Sara's awesome abilities

and years of training allow her to make an attempt like this.

Don't ever try something like this yourselves.

Sara has been down for nearly two minutes.

So far, she is fighting the body's natural desire to breathe,

but there's still a long way to go.

The most dangerous part of this dive is the last ten metres.

This is usually the point that freedivers black out

from lack of oxygen. And it's happened to Sara herself before.

For that reason, it's essential that a safety freediver is waiting

to guide her up for the last stretch.

If she blacks out now, he'll need to save her.

Sara, that was truly one of the most magical things I've ever seen.

You are one of the most incredible people I've ever met.

It's just been a pleasure sharing this wonderful sport with you.

I came to the Emirates to find a real-life superhuman,

a person who could dive deeper and longer than any normal human.

I found one. Sara Campbell, you are superhuman.

Sara Campbell is one of the world's top freedivers,

with years of training and experience.

Do not attempt any of the activities shown in this programme.

You will be putting your life in danger.

Subtitles by Red Bee Media Ltd