Northern New South Wales Coast Australia

This is as far east as I can possibly go

on mainland Australia.

This is the coast of northern New South Wales,

where the Pacific Ocean crashes onto a subtropical shore.

From this point, the next landfall is South America,

11,000km that way.

We've come here to explore this eastern extreme

on a coast sought after for its serenity,

where a relaxed lifestyle hides a history of danger

and adventure.

Joining me on this journey,

Dr Alice Garner goes to visit a most extraordinary jail.

It was a hive of activity.

There was a barbershop, a tailor,

a cobbler.

Professor Tim Flannery uncovers

a little-known tale of heroism and exploration.

12 men, small rafts,

total isolation for six months...

It takes a special kind of person to survive that.

Professor Emma Johnston goes deep

in the search for hidden killers of an endangered species.

These critical habitats are vital to their survival.

While I investigate a secret war

the authorities were determined to cover-up.

The government certainly didn't want it to be public knowledge

in case the populace got panicked.

This is Coast...

Australia.

Our journey along northern New South Wales

stretches from Byron Bay

through the port of Yamba,

Coffs Harbour,

and on to South West Rocks.

In 1770, Lieutenant James Cook

passed this cape on his journey up the east coast...

..stopping just long enough to name its sweeping bay

after fellow circumnavigator, Lord John Byron -

grandfather of the famous poet.

The region's most prominent landmark

is undoubtedly the Cape Byron lighthouse,

which has stood sentinel over this stretch of the Pacific since 1901.

With a beam that can be seen 27 nautical miles out to sea,

it's one of the most powerful lights in the southern hemisphere,

but, as much as it wards off ships, it draws people in.

Most lighthouses are the epitome of isolation,

but this one, due to its location,

has been reluctantly accessible to visitors from the very beginning -

so much so, that in 1958, stressed by the constant flow of tourists,

the keeper Harry Handicott applied for a transfer.

Old Harry would have conniptions if he could see it today.

Each year, at least half-a-million visitors swarm to the lighthouse,

climbing up to the lamp gallery to take in the truly stupendous view.

But it's more than just the iconic lighthouse and dazzling landscape

that draws the crowds to Byron.

The town radiates an earthy energy creating a modern day Mecca

for those seeking an alternative lifestyle,

and a magnet for cashed-up sea-changers

in multimillion dollar mansions.

But the beauty and the laid-back lifestyle of this place

hides a dirty past.

Leading surfboard designer Bob McTavish

witnessed that past first hand.

Coming here in the mid-'50s, Bob found himself on the crest of a wave

in more ways than one,

spearheading a surfing invasion,

which changed Byron forever.

For a non-surfer like me,

why is Byron Bay so good?

This break - The Pass -

is probably the longest right-hand wave

on the east coast that's easy to access.

And it's so consistent.

There's good surf here maybe 150, 180 days a year,

which is pretty rare for any place in the world,

to have surf that frequent.

But the Byron Bay Bob and his surfie mates discovered half a century ago

was no relaxed resort town,

it was a staunchly blue-collar industrial hub.

The locals were far more concerned with pay packets than point breaks.

So when you were here in the early days it was this contrast -

side-by-side you had a physical paradise...

Yep.

..and a lot of heavy industry,

and people earning a living at the same time?

Yeah, first it was the timber industry.

All the beautiful Louis XIV furniture was made out of all the trees

that grew around here,

and was all shipped back to Europe.

And by 1905 it was the biggest dairy processing place in the southern hemisphere -

functioning right here in this town.

And the rich pastures of the hinterland

also produced a thriving beef industry.

Between 1912 and 1983,

an abattoir sprawled on a prime cut of surfside real estate.

You just don't associate that kind of set-up with Byron Bay.

-Or I don't.

-It's a full-on industry.

And out here there's a blood pipe,

and every afternoon the blood and bits of offal and hair and stuff

would all be flushed straight into the ocean,

and the sharks were around there, like...

"Arh-yarh-yarh... Where's the food?!"

They've got all the chum but nothing to eat,

so we used to avoid surfing there in the afternoons.

But those early surfers had more to fear from local police

who took a dim view of these long-haired newcomers,

branding them a threat to Byron's hard-working way of life.

See this classic headline -

This Is One Place The Surfies Aren't Taking Over -

and that's the local police sergeant.

That's not the kind of face you want to see looming over you

-if you're a long-haired surfie bum, is it?

-It's not!

It's not going to end well.

No, not going to end well!

And what kind of grief did you get from the police?

One time I lobbed here with my friend Terry,

cop car came screeching down the dirt track.

The guys jumped out, and they drove us down to the local barbershop

and said, "Give 'em a crew cut!"

So they buzz-cutted us both

and put us in the lock-up for the night.

Because we had long hair.

A stinking abattoir,

a huge dairy factory...

It's hard to imagine such things in a paradise location like this one.

You might imagine this sand had always been sacred,

but apparently not.

From 1933 to 1962,

a large sand-mining operation was based right here.

One man who can shed light on this part of Byron's less-than-perfect past

is historian Robert Smith.

So this beach wasn't always a surfer's paradise then?

Oh, no, no, no.

Where we're walking was actually sand-mined.

There were big holes here -

bulldozers, trucks coming in,

sand was being shipped out.

It was a big industrial site.

And what was it that was making the sand valuable?

Why were they mining it?

Ah, well, that was the mineral sands, as they're called -

particularly zircon, rutile.

Those minerals were used in the lucrative aeronautics industry.

Apart from leaving huge craters in the beach,

the mining resulted in a far more serious problem.

Leftover sand was dumped at sites all over Byron Bay.

Only much later did they discover

that it contained traces of uranium and thorium.

Somebody decided to put a Geiger counter over their block

and found that it was highly radioactive.

And has that been dealt with?

Yes, it was a massive clean-up operation in the '80s.

As if digging up the beach and dumping radioactive waste

wasn't bad enough,

Byron Bay was also home to a short lived whaling industry

that started in the 1950s.

Between May and November,

on average two humpbacks were killed and processed every day.

It attracted massive crowds - crowds of thousands -

coming in to see what a whale looked like

being dragged from the sea and then cut up.

Seems amazing, you know, in these times of whale-watching

that, back in the '50s and early '60s,

the whales were a tourist attraction

for a completely different reason.

That's true. It's true.

Families could come and see the whales being cut up -

that's how whale-watching operated in an earlier era!

It's hard to reconcile modern Byron Bay

with its sometimes ugly past.

Yet, in one way, those hard times paved the way for today's splendour.

One of the benefits of polluting, smelly industries

persevering in Byron Bay for so long,

was that it constrained development.

So that coastal tourist development

that seemed to overrun some other coastal centres

didn't happen here.

And, in a sense, it's preserved

what many of us think is the best of the community.

The industry, in its own way, protected the coast.

Yeah, you could say that. Yes.

It's quite a transformation.

Byron Bay has outlived and outgrown its unclean past

and it's done that by embracing the beauty

and cherishing the bounty.

It goes to show that the only constant on the coast

is change.

Australia's European history

is defined by intrepid souls,

who braved a long and arduous journey

to arrive on this coast.

Tim Flannery's passion for explorer history

has led him to the town of Ballina

where an Odyssean adventure arrived on these shores

40 years ago.

If you stand on a break wall like this long enough,

you're bound to see all manner of strange things.

But if you'd been here on 21 November, 1973,

you would've seen something that was truly unique.

-REPORTER:

-'The small fishing port of Ballina woke up to find itself

'the centre of national attention.'

People turned out in numbers to welcome the arrival of 12 men,

who had just completed the longest recorded, nonstop raft journey

in history.

Over six months this crew

from seven different countries

had travelled 14,000km

from Guayaquil in Ecuador to Australia...

..in three traditional South American vessels,

made only with balsa wood and sisal rope.

'The object of the voyage

'was to show that the Indians of South America

'could have navigated across the Pacific in similar rafts

'hundreds, and even thousands, of years ago.'

In support of their adventure was Salvador Dali.

He painted a sail which he gave to the crew as a gesture of solidarity

with those brave sailors.

All three rafts made it to Australian waters,

but when one became waterlogged it was abandoned,

and later washed up in Newcastle.

-Good to meet you.

-Nice seeing you.

John Zentveld was amongst the welcome party

when the remaining two rafts appeared.

So, John, what were you doing on that day 40 years ago?

Well, when we heard on the radio

the rafts were coming in

we decided, well, to take the boat,

throw it in the water and let's go and have a look at 'em!

The first raft came in,

waving like mad.

It was an exciting scene for us,

but it was, of course, very, very exciting for them.

There it is, 21 November, 1973.

There's the two rafts

and there are the boys - my goodness!

They look like Robinson Crusoe, don't they?

Well, they hadn't had a shave for a long, long time.

I reckon. My goodness.

THEY LAUGH

12 men, small rafts,

total isolation for six months.

It takes a special kind of person to survive that.

The navigator of the group was 28-year-old Chilean geologist

Hugo Becerra.

-Hey, Hugo!

-Hi.

That was a pretty crazy journey you made, by the sound of it.

Whatever inspired you to do it.

Well, I was young and looking for adventure.

Adventure, indeed, but it also turned out to be a lucky escape.

While they were at sea, the brutal regime of Pinochet

had taken power in Hugo's homeland of Chile.

So you were responsible for navigating.

Were you qualified for that?

No. I wasn't qualified for anything on the raft, really.

THEY LAUGH

Not even for sailing.

Hugo quickly mastered the sextant

and with his university mathematics,

plotted their course each day.

So you must have faced dangers out there, surely.

Well, storms, yes.

Ballina's Naval and Maritime Museum

houses what remains of the historic rafts.

Ah, wow!

That's a lot bigger than I thought it was going to be.

I can see the cabin through there. It looks very small.

-I'd like to go and have a look.

-I'll show you there.

Living conditions were tight,

with four men on each raft -

14 meters long and 5.5 metres wide.

Now you can't tell me there was any privacy on this boat.

No, no privacy, at all, but it was very comfortable.

Only a bamboo hut offered a hope of privacy,

and some protection from the elements.

Welcome aboard, Chief Navigator.

I'm sorry I haven't got a whistle to pipe you...on deck with.

This is the first time that Hugo has set foot on the raft in 30 years.

Now, over here, this was the toilet.

It looks reasonably comfortable.

It was very comfortable.

Did you ever have any water coming up from below?

Yeah!

I haven't heard about this expedition very much at all,

and I've lived in Australia all my life.

Do you think it's been forgotten?

Well, I think so. Yeah.

-It's like growing up, becoming a man.

-Yeah.

A few weeks after arriving,

most of the crew had returned to their respective countries.

But Prime Minister Whitlam granted Hugo and his Chilean crewmate

sanctuary in Australia.

As for the Dali sail -

it was sold by the crew for about 50,000 in 1983,

and used to repay their respective debts incurred in travel

back to their home lands.

The ocean along the northern coast of New South Wales

attracts many wanting to reap its bounty.

Passionate anglers will often jealously guard

the secrets to fishing success.

When some locals discovered a bountiful fishing spot

just off the coast here a few years ago,

they had no intentions of telling anyone about it.

But they didn't realise they had found something much more precious

than a rich marine harvest.

In fact, they'd stumbled upon a silent monument

to a secret history.

A theatre of war that reached to the very edge of Australia.

Sally and Forfar Petrie and their friend Neville Poynting

have agreed to take me to the site of their serendipitous discovery.

ENGINE STARTS

A once-secret fishing spot about 10km off the coast of Ballina.

Can you tell me about the day when you found the fishing spot?

It was a perfect day, there was flat seas...

And I had my sounder on

and this mark came up.

Just this huge... And it looked like a big ball of bait fish.

We turned around, had three rods out,

and bang! Fish on.

Right. Did you know, as fishermen,

you'd found something out of the ordinary?

Oh, yes, yes...

I knew I'd found El Dorado!

THEY LAUGH

That was in 2006.

For five years they kept their secret,

never questioning why this place produced such a rich harvest,

until one day they noticed droplets of oil

on the surface.

At that stage I was talking a lot

with the director of the Heritage Society and I sent him down

a little sample of oil I collected in a plastic bag.

They identified it as diesel oil.

And there was no other explanation for oil like that being on the seabed

except if it was inside a ship.

Exactly. Exactly.

A CSIRO survey ship was bought in,

and 3-D mapping of the seabed revealed the truth.

The Petries' fishing hot spot was, in fact, an enormous wreck,

which had become an artificial reef - a magnet for marine life.

The wreck was soon identified as a World War II merchant vessel

called the MV Limerick.

Some called the Limerick the Titanic of her day.

When launched in 1925,

she was the fastest merchant vessel in the world.

But like the Titanic,

the Limerick was doomed.

The Limerick lies 100 metres below me here.

She was sunk by a Japanese torpedo during World War II.

It's a sobering reminder that this calm expanse of water

was, at that time, a violent theatre of war.

The Limerick was travelling in convoy from Sydney to Brisbane

on a mission to pick up and deliver vital war supplies to England.

Overnight between Anzac Day and the 26 April, 1943,

a Japanese torpedo found its mark.

This war in Australian waters killed 654 people,

including 200 Australian merchant seamen.

You might not have heard much about it,

because it was kept quiet.

Why?

Because the Australian Government believed news of all these sinkings

would cause mass panic,

they ordered a media blackout.

Remarkably, only two people on board the Limerick

died in the attack.

70 men were plucked from the ocean,

including the ship's radio officer George Jones.

For George's son Warwick,

the sinking of the Limerick became a lifelong obsession.

How did you feel when you learned that the wreck had been discovered?

Gobsmacked, I suppose.

It seemed unreal.

I never expected the ship to be found.

Warwick was always fascinated

about the tale of his father's narrow escape.

My dad had come off watch at midnight,

had a cup of coffee, turned in to bed,

and at four minutes past one there was a fearsome explosion

which threw him out of his bunk.

The ship was in chaos, darkness, no communications,

and so they made the decision to abandon ship.

This is his original handwritten diary, where he says,

"So down the rope on the starboard side

"where a large part of the ship's side was exposed,

"and into the water.

"All was dark and silent

"and I then began to think my chance of survival was slim indeed."

Just that little passage, ah...

speaks to me of his desperation

"and the strong possibility that the end of his life was nigh."

How long was it from going into the water, before your dad was rescued?

They were in the water for a bit over seven hours.

At what point, after the sinking,

was your dad and the other men told they couldn't talk about it?

Probably at the intelligence briefings in Brisbane

immediately after the event.

The government certainly didn't want it to be public knowledge

in case the populace got panicked -

knowing the proximity of the Japanese

and the damage they were doing off the east coast of Australia.

The silence that was thrust upon them,

did nothing to suppress the horrific memories.

For the rest of his life,

George suffered recurring bouts of post-traumatic stress disorder.

What form did that take?

He became functionally catatonic -

unable to speak,

a thousand-yard stare.

It must've been a terrifying experience.

Finding the Limerick's final resting place is a stark reminder

that for most people along the northern New South Wales coast

the war came and went,

without them ever knowing of the conflict

raging on their doorstep,

one that left men like George Jones battling an internal foe.

What I know about post-traumatic stress disorder

is that it follows you around for most of the rest of your life.

And so, from that point of view, I have, at this juncture,

nothing but admiration for my father,

that he didn't let it affect him, and that he conquered it.

North of the city of Coffs Harbour,

verdant hills lollop and roll

to the water's edge.

Once known as the Banana Coast,

recent decades have seen farming shift towards blueberries,

which grow well in the sandy soil

and frost-free coastal clime.

Brendan Moar is visiting the peaceful hamlet of Woolgoolga

to discover the roots of its distinctive cultural flavour.

Walking along a stretch

of the northern New South Wales coast like this,

the first thing I think is

"How can I live here?"

A little block of land with that beach as your doorstep -

you can see why that is part of the great Australian dream.

A dream enjoyed here in Woolgoolga

by Australia's largest regional Sikh community.

TRADITIONAL MUSIC

I figured the weekend Bollywood On The Beach markets

might be the place to find out more about this flourishing group.

Bollywood On The Beach is just like India -

a lot of people and some curry.

Very nice!

When he's not selling curry,

John Arkan is a local councillor and blueberry farmer.

-John.

-Welcome, sir.

-Brendan.

-Brendan, welcome.

I haven't met you before. You are coming from India?

No, no, I'm not from India,

but I suspect that you may well be!

Yeah, that's right, I come from India. That's it.

So your parents came here...

My grandparents came in 1895.

We're farmers from the north of India,

so we came to the Clarence Valley

where we did sugar cane farming.

And as the story goes, one gentleman came here to Woolgoolga

looking for extra work,

and they discovered the banana farms here.

And word got out, and people started turning up here after, and during, the war...

-Other people from...

-Other Sikhs.

-From Punjab?

-From Punjab.

As citizens of British India,

of the Commonwealth,

and later having fought alongside the Anzacs at Gallipoli,

Sikhs could benefit

from the Australian government's immigration encouragement policies,

making travel to and from Australia much easier.

From the 1920s, and during World War II,

the numbers of Sikh father-and-son workers increased,

particularly around the New South Wales northern rivers.

But the greatest influx came after the partition of India in 1947,

when the state of Punjab was divided into Islamic Pakistan in the west

and secular India in the east.

The tumult at home drove many to the Coffs Coast for good.

So then in about 1968, the first Sikh temple in Australia was built here.

And then that's just like every other human need -

once we have a place to worship and a place to work,

everybody started turning up.

Nearly a quarter of the 5,000 people

who live in the region are Sikhs,

and they own 90% of the local banana and blueberry farms.

-So you are Sikh?

-I am.

For me it means to be a person

that fully embraces everything and every place

that they're involved in.

So, when I'm selling curry, wherever I go,

I deliberately speak with everybody.

Because for me, I'm embracing God.

I'm embracing whatever they are.

It doesn't matter - we're all human beings.

It's my turn to do a little embracing.

MUSIC PLAYS

It's a mark of tradition for John's wife Surinder

to lead the dance circle.

Back to where we were!

Brendan, you've got a really good rhythm, man!

And I'm not going to hold my breath waiting for a call from Bollywood.

Look at that!

One thing makes me curious.

Coming as it does from a landlocked state,

how has this vibrant cultural tradition

blended with Aussie beach culture?

We're a part of the coast. The kids come down, the uncles and aunties...

This is the gathering area.

So, the coast is actually becoming what the big tree used to be

in the villages in India.

A place to gather, to discuss what we are doing during the day,

to have that interaction between the elderly and the young,

and to work out where the village is going.

That's what's happening on the coast in Woolgoolga.

The Sikhs left India looking for a new life and a new beginning,

and many decades later

they have stayed completely true to who they are,

at the same time totally embracing this Australian coastal life.

Just 30km south of Woolgoolga,

Xanthe Mallett is in for the ride of her life,

as she checks out the high-octane world of offshore powerboating.

Early morning, beautiful and tranquil Coffs Harbour.

People come here to relax

and enjoy the ambience.

Let's shake that up a little bit, shall we?

-Good morning.

-Good morning.

Meet Conn Saloumidis...

..card-carrying member of the big boys' toys club.

His plaything?

A supercat 600 offshore superboat

which he built three years ago.

Buy one new, and it'll cost you north of half a million dollars.

There are only 20 superboats in Australia

and this is the only one in New South Wales.

-This is where all the magic happens.

-Absolutely!

This is 300 horsepower.

-So, you've got two of those.

-Yep.

Now, that sounds pretty big to me. What is that equivalent to in a car?

Er, V8 supercars, I think, are about 550 horsepower.

This carbon fibre and Kevlar beast is a far cry

from the timber powerboats of yore.

In the 1950s, the sport was dominated by

American racing car enthusiasts and yacht designers,

but Australia had its own pioneering speedster, Ken Warby,

who set the world water speed record in 1978.

His backyard-built, jet-engined Spirit Of Australia

clocked 511kph -

a record that still stands.

Over the next decade,

powerboat racing gained even more rev-head recognition.

It came to prominence in the '80s with America's war on drugs.

They were bringing a lot of drugs in from South America via boats,

and the boats just got faster and faster.

That power comes at a price.

HUGE ENGINE REVS

Conn's boat burns 1,500 worth of fuel in a single race,

but, if it's high-octane thrills you're after -

hey, it's money well spent!

To get a sense of speed, we are going flat out at 60Ks an hour.

But look at this!

Now I've seen that, I've just got to have a go.

Come on aboard.

All right. My turn.

Ohhh...! OK, thank you.

What are the safety features you've got in here?

-Because it's a pretty dangerous sport.

-Absolutely.

Well, your five-point harness.

There's breathing apparatus just there beside you.

Ah, also, the snorkel,

in case it goes over and you're underwater,

you can actually still breathe.

Put that in until they rescue you.

Travelling 100km south of Coffs Harbour

along endless stretches of majestic beaches brings us

to the South West Rocks area -

a haven for one of Australia's most ancient and special marine species.

Professor Emma Johnston has come to investigate

what's threatening these creatures.

Sharks have a fearsome reputation as man-eaters,

but of the 400 or so species in the world,

only three are responsible

for most attacks on humans -

tigers, bulls and great whites.

Yet all of the sharks, even the most harmless ones,

suffer the consequences of our fear.

I am here to investigate one such species.

With its menacing mouthful of teeth,

the grey nurse shark appears every inch a killer.

But looks can be deceiving.

These sharks are not man-eaters.

Sadly, people have attacked them.

In the '60s and '70s,

working on the theory that "the only good shark is a dead shark",

hunters slaughtered the great nurse,

at times killing up to 30 a day.

That, coupled with their slow reproductive rate,

has left the grey nurse in danger of being wiped out

from the east coast of Australia.

Dr Nick Otway, a marine ecologist,

has been studying grey nurse sharks for 15 years.

-How are you going?

-Not bad, how are you?

The species is protected from hunting,

but the impact of humans is still a threat.

Their teeth are actually designed for just eating fish.

They're feeding on a whole range of fish

that commercial and recreational fishers will also target,

and are out there trying to catch.

Can we have a look at those teeth?

Yes. Absolutely.

-We've got the jaw.

-Beautiful.

So they're there to grab hold of the fish,

and then, it swallows the fish whole.

In that sort of situation,

if you have got a fish on a hook,

then it's actually taking the hook into its gut,

and that has consequences for the animal.

Nick is leading a long-term research project

to assist the recovery of the grey nurse sharks

along the east coast of Australia.

This 2.5m grey nurse was caught in a shark net off Sydney.

Nick suspects the corpse will hold clues

to other threats facing the population.

So I'm going to help him conduct a postmortem examination.

First, the shark is weighed.

So, what weight would we expect?

We'd expect about 100kg.

Well, we've only got about 75 here. 74?

What does that indicate?

We'd suspect that there's some sort of hook damage,

or the animal is diseased.

Examining its exterior reveals a telltale sign.

You can see here...

That could very well be a past hook wound that is healing.

Time to inspect the internals.

Because this animal has lost weight...

They can lose weight from their body mass - their muscle mass -

but they can often lose weight from their liver.

And when they lose weight from their liver, the liver really goes dark.

Almost a dark blue to black.

And if you look at it here - this animal's lost weight,

and look at the colour of the liver.

-That's one low liver.

-Oh...!

-So that's indicative of a sick...

-Of an unhealthy animal.

-Yes.

-OK.

What can cause disease in the liver of a shark?

A range of things, especially hooks.

There's good evidence from work that's been done in the United States

that the retention of hooks causes all sorts of diseases,

including cancer, in sharks.

The offending hook is long gone,

but the infection it caused damaged the shark's liver.

This would've killed it 25 years earlier than a healthy grey nurse,

who have a life expectancy of 35 years.

Studying dead sharks can tell you only so much.

It's time to suit up and observe these gentle creatures

in their own element.

Grey nurse sharks roam over really large areas

of the New South Wales coast,

but they're known to gather to feed, mate and pup

in only a small number of locations.

These critical habitats are vital to their survival

and we're going to visit one today.

We're heading just off the coast of South West Rocks

to shoot some sharks...

with a camera.

Two cameras, in fact.

It's new technology called stereo photogrammetry.

Two cameras...

They're angled in at four degrees,

and what you get is overlapping images,

and that enables you to actually get the lengths,

and any measurements that you want to get, from the shark.

And you'll get very, very accurate measurements.

This is grey nurse central -

smack-bang in the middle of their migration zone.

In the protective shelter of these deep gutters

the sharks congregate to feed and mate.

It's soon obvious why they're sometimes called

Labradors of the sea.

This is truly remarkable.

Five grey nurse sharks

much, much larger than me,

swimming only a metre away.

This new technology will provide Nick's team with vital data

not just on size,

but on age, weight and sex...

..building up an in-depth profile of this population -

all without having to touch a single shark.

In 1984, the grey nurse became the first shark species in the world

to be awarded official protection.

But with females only reproducing every second year,

it is estimated there are only 1,500 sharks left here

on the entire east coast of Australia.

How many would you need in a population

before you would be comfortable that the population was viable?

Well, worldwide studies on a whole range of animals,

including sharks, have essentially said that

for a population to be viable,

and to stay viable into the future,

you need about 5,000 animals.

So we've got well below that.

It's really humbling to have swum with such gentle creatures.

They are just very calm.

They look like they've been here for hundreds of thousands of years,

and they have, actually, been here for hundreds of thousands of years.

This is THEIR home.

And, hopefully, with some research,

with some better management,

this will be their home for many years into the future.

Near the seaside town of South West Rocks, the glistening jade

expanse of Trial Bay invites the most languid of pursuits.

Overlooking the peaceful bay sits a relic fortress, a jail,

with a curious wartime history.

Dr Alice Garner is following the clues to the heyday of these ruins.

Over 90 years ago,

two young girls were exploring these cliffs up here,

when they came across the most unlikely treasure.

This portrait of a mystery man.

The man's identity and his link to Trial Bay Gaol

would remain an enigma for 80 years...

-Hello.

-Hello.

..until German-born historian Nadine Helmi

finally put the pieces of this puzzle together.

Tell me, who is the man in the painting?

Well, I found out that it was Paul Dubotzki,

a young, very talented photographer from Bavaria.

Nadine realised that Paul Dubotzki,

the man in the photo,

was also the man in the painting.

And he was interned here at Trial Bay Gaol

during World War I.

Trial Bay Gaol was built in the late 1800s.

Prisoners began to construct a breakwater,

but that project was abandoned

and the jail closed until the First World War.

In 1915, our man in the painting, Paul Dubotzki,

was a professional photographer

who had recently arrived in Adelaide.

At that time about 100,000 people

of German or Austrian heritage lived in Australia.

Paul was one of nearly 7,000

who were deemed enemy aliens -

a threat to national security -

and sent to internment camps

around the country.

But the men sent here, to Trial Bay,

were a very particular bunch.

There were about 500 wealthy, well-educated members

of the German upper class.

Why were they separated out from the other internment camps?

It was class thinking.

They wouldn't want to mix the upper class, you know,

with the bottom part of the internees.

Was Trial Bay run differently from the other internment camps?

It was run mostly by the internees,

and there were similarities,

but they were really privileged,

because they could go outside the jail

enjoying a bit of freedom during the day.

You can see the chamber orchestra,

everybody meticulously dressed.

And here...they all are in their Sunday's best

hanging out at the Strandcafe,

which means beach cafe.

So they're recreating the comforts of home?

Absolutely.

You know, so you go out and enjoy coffee and a piece of cake.

As you do in Germany.

It's clear that this was no ordinary jail.

It was a hive of activity.

There was a barber shop,

there was a tailor, a cobbler,

and not to forget, of course,

Mr Dubotzki, Paul, had his photo shop.

Ever ready with his camera,

Dubotzki snapped more than 1,000 photos during his internment.

Those pictures reveal that Trial Bay didn't really

live up to its name.

The Germanic inmates built a sophisticated and refined community.

Here stood the theatre -

the Deutsches Theater Trial Bay.

And it was quite a substantial, purpose-built theatre.

It could seat about 200 internees

and churned out, you know, once a week or fortnight,

a new show.

It was done with passion by volunteers who had the urge

to do something creative, artistic.

And they served a very important purpose,

because, for the internees, it really was very therapeutic

to come and see this life on stage.

This life that they were missing.

The lack of women didn't deter these amateur thespians.

Instead, they observed a long-held theatrical tradition.

After a little bit of hesitation,

there were a couple of internees who said,

"OK, we go on stage and we'll impersonate women."

And so they did.

Look at this incredibly glamorous shot.

So, you get an idea,

what kind of women they could see on stage,

and maybe dream to spend some time with!

What's clear from Dubotzki's photos

is that the internees at Trial Bay had a fair degree of freedom.

I mean, they were even allowed

to build little beach huts all around here

and sell them to each other.

The internees spent three years in their seaside paradise,

but it all came to an abrupt end in May 1918,

when the government suddenly shut down the facility.

The prisoners were given just 48 hours' notice.

In fury, these men, who had led such cultured lives,

trashed and burnt their barracks,

turning everything they'd created to ash.

In the rush to leave,

Paul Dubotzki must have hidden his portrait in the dugout

before being deported to Germany

along with most of his fellow internees.

He later set up a photography shop in Bavaria,

married, and had a family.

Many internees stayed in touch,

with frequent reunions in Hamburg until 1973.

Trial Bay Gaol lies silent and empty now,

but the spirit and ingenuity of the internees' community

live on in Dubotzki's unforgettable photos.

Sitting pretty in the middle of the most pristine stretch of coastline

in northern New South Wales

is the popular holiday town of Yamba,

famous for its favourable climate.

Temperate winters and warm summer days ensure that here,

the slow lane isn't hard to find.

Today I'm going looking for something

that moves surprisingly quickly

but is much harder to find.

In fact, to my untrained eye,

it should be all but invisible.

Moninya Roughan is a mathematician

specialising in coastal oceanography.

Today we are heading a few kilometres offshore

to the continental shelf

in search of an underwater superhighway.

Where exactly are we now?

So we've come here to the edge of the East Australian Current.

It's one of Australia's major ocean boundary currents.

So the warm water in the equator, basically,

pushes southward down to the cold of the poles,

bringing warm water down the coast all the time.

The East Australian Current

is up to 100km wide

and more than 300 metres deep -

a massive movement of water which moderates our climate,

bringing warm, humid weather to coastal New South Wales.

I think it's a strange feeling to know that we are on the edge

of something so massive that it actually affects the planet.

You get a sense of what it must look like from outer space, or something.

This vast body of water on the move.

Moninya and her team from the University of New South Wales

are using cutting-edge technology

to decode the secrets of this crucial current.

This is an ocean glider,

and we use it to measure the properties of the East Australian Current.

-Does that just go off on its own?

-Absolutely.

It's totally autonomous.

We send it out, and we don't see it for three or four weeks.

Once you let it go, how do you get it back?

It's got a little satellite tracker on it,

and we can program it to dive, but also to come up to the surface.

So when it comes up to the surface,

it relays its position via satellite back to our computer.

Right, so it tells you where it is?

Yeah, it's really cool.

And is it vulnerable in the water?

Um, yeah, it can run into obstacles like islands, or rocks, or boats,

but, er, you know, it also looks a little tasty

for marine predators, as well.

These are marks from shark teeth?

Yeah, absolutely.

-And a mouth...about that wide.

-Yeah.

The glider is swept south in the powerful ocean current,

diving deep and surfacing at regular intervals...

..all the time collecting data which is relayed to the lab via satellite.

What information do you get from it?

So it's measuring the temperature and the salinity,

and the pressure, as it goes up and down,

but also the light - the amount of sunlight -

that's penetrating into the water.

So, now that we've deployed it we can go back inshore

and I can show you some of the data.

The glider will spend three to four weeks

on its underwater mission,

weaving in- and offshore covering

over 400km on its way south to Port Macquarie.

How quickly do you start to get feedback from

the glider that went in today?

Well, it's been about an hour,

so we should be able to get some data now.

-So it's real time?

-Yeah.

-There it is.

-Right, what does that mean?

So here we have the temperature, at the surface.

So it's a combination of temperature and salinity, and pressure, as well.

It's a strange feeling to know that it's out there doing that just now.

It is a bit like a space mission, isn't it?

It's like sending something out into the unknown.

It's... It's incredible. The ocean IS the last frontier.

70% of our Earth is ocean and we know so little about it.

How is the ocean here changing?

We have evidence to show that the oceans ARE warming.

We have a monitoring site off the coast of Tasmania, erm...

with 70 years of data.

70 years' temperature records off the coast of Tasmania.

We can see that the surface temperatures have warmed 1.8 degrees.

So this information we're collecting is really important

for contributing to these databases and really understanding

what the conditions are now,

so that we know in the future how warm the oceans are getting.

In a few weeks' time,

Moninya and her team will be in another boat

hundreds of kilometres from here

to collect the glider and to begin crunching the numbers

that will help them to predict, and even influence,

this part of the coastline.

That's assuming a shark doesn't swallow it first!

Next time, we visit Australia's south-west.

Brendan Moar discovers an intrepid botanical collector.

Lords and ladies were going wild

wanting the stuff that she'd sent.

Xanthe Mallett joins a police exercise to recover lost bodies.

A lot of silt's been kicked up

which complicates the bodies' retrieval.

And for me, the true story

of a bizarre drama on the high seas.

You fire on us, you're firing on America.

Do you want to start a war?