Georgina: And I'm Georgina.

Neil: Now Georgina, what do you know

about free diving?

Georgina: Free diving is a sport where

people dive underwater

as deep as they can without carrying air

tanks, so just by holding their breath.

Neil: That’s right. We’re going to find out

today about a world record free diver. But

first a question – and this is a physics

one. On dry land, at sea level, the pressure

or weight of all the air above us is known

as an atmosphere. How far underwater

do you have to go until the weight of

water is equal in pressure to another

atmosphere? Is it:

A: 1 metre, B: 10 metres, or C: 100 metres

What do you think, Georgina?

Georgina: Well, water is much heavier

than air, but there is lot of air above us,

many kilometres, so I don’t think one

metre of water is heavy

enough. Same for 10 metres. So, I think

100 metres is the equivalent of

1 atmosphere.

Neil: OK. We’ll find out if you are

swimming comfortably

or completely out of your depth later.

Herbert Nitsch holds the world record for

the deepest free dive. In 2012 he reached

a depth of 253 metres. Recently he spoke

on the BBC World Service radio

programme, Outlook about his

experiences. He spoke about how he

trained himself to hold his breath for a

long time.

Lungs are the organs in the body that hold

the air that we breathe in, and he says

that he trains himself not by starting with

a big breath, but when his lungs are

already empty. Why is that?

Herbert Nitsch: The reason why I do the

empty lungs is that the urge to breathe

comes earlier and this is when the

training starts. Because when

you hold your breath on full lungs, the

urge to breathe comes a few minutes in,

but the time up to that point is no training

at all. Only the time you have the urge to

breathe and fight against it, that’s the

time you're actually training.

Neil: So, why train with empty lungs?

Georgina: Because you have to practise

not breathing when you need to breathe.

Neil: Can you explain further?

Georgina: Of course. Normally our

breathing is automatic.

We don’t have to think about it. If you

hold your breath there is a point when your

body tells you that it’s time to breathe.

Neil: And at that point, most of us will

take a breath, won’t we?

Georgina: Exactly. Our body and brain is

telling us – go on, breathe, take a breath!

This strong feeling to do something is

called an 'urge'.

To hold your breath for a long time you

have to ignore that urge, you have to fight

against it. So to train to do that, it’s a

waste of time taking a big breath,

because holding your breath when you

don’t need to breathe isn’t difficult – you

have to practise fighting against that urge

to breathe.

Neil: Nitsch did a lot of free diving in lakes

in his home country of Austria. Diving in

lakes is very different from diving in the ocean.

Here he is describing the experience.

Herbert Nitsch: In the beginning it’s very

spooky, and yes, it’s not a pleasant feeling

at all in the beginning. It’s something

actually quite intimidating, but after a

while you get used to it and you learn to

appreciate it actually that it’s so quiet.

Quiet and you’re deprived of all

sensations except the cold, of course,

and so you hear your own heart beat

because there’s absolutely no sound.

Neil: How does he describe the sensation?

Georgina: It’s very cold, dark and quiet

when diving deep in lakes and at first he

says the experience is 'spooky'. This

means it’s a little scary and mysterious –

in the same way we might find a

graveyard at night spooky – that

kind of feeling.

Neil: And he also says it’s 'intimidating',

which is a feeling of being frightened by

something stronger and more powerful

than you are.

Georgina: And you experience these

feelings because you are deprived of all

sensations. When you are 'deprived of'

something, it means you don’t

have it, it’s taken away. And sensations

are the way we experience the world, so

sound, sight and smell. Diving in cold,

dark silent waters you are deprived of

many of our usual sensations, and that is

spooky and intimidating.

Neil: Rather him than me. I don’t think I’d

like that experience at all! Right, before

we review our vocabulary, let’s have the

answer to the quiz. How far underwater

do you have to go until the weight of

water is equal in pressure to another

atmosphere? Georgina, what did you say?

Georgina: I thought 100 metres.

Neil: Well, that is actually the equivalent

of 10 atmospheres! So the correct answer

is 10 metres. Every 10 metres of depth in

water is the equivalent to the weight and

pressure of the air above us at sea level.

There is a difference between

fresh and salt water, but it’s not so much

as to make your answer correct!

Well done if you got that answer right.

Georgina: Well I was clearly out of my

depth with that question.

Neil: You were! Now vocabulary. The part

of our body that holds our breath is our

'lungs'.

Georgina: A very strong need or desire to

do something, like breathe, is an 'urge'.

Neil: Something 'spooky' is a little scary

and mysterious.

Georgina: And it can also be 'intimidating',

which means it’s overpowering and

frightening in a way that makes you less confident.

Neil: And to be 'deprived of' sensations,

means to have certain feelings, like touch

and hearing taken away. So Georgina, do

you fancy free diving?

Georgina: Would I like to go hundreds of

metres down in cold, dark, silent, water

without any breathing equipment? Let me

think about that. I’ve thought about it –

no thank you!

Neil: Not my cup of tea either – and

speaking of tea, it is time for us to go and

get a cuppa. That’s all from us. Do

join us next time and if you get lonely, you

can find us online, on social media and on

the BBC Learning English app. Bye for now.

Georgina: Bye!