The oceans are places of wonder.
Blue Planet II showed us the beauty and extraordinary behaviour of
marine life, whilst highlighting how fragile and threatened our seas
have become.
Now, as Blue Planet Live carries out a health check
on the world's oceans, we are staying closer to home.
Our British seas are rich, varied,
and key to our island heritage,
but how are our lifestyles affecting them?
Whoa!
We'll meet the unsung heroes dedicated to protecting our waters
and the wildlife that relies on them...
If we don't look after nature nobody else will.
And celebrate the scientists striving for solutions to
the challenges.
Whoa!
Plus, we'll meet the crabs with a flair for style...
They're dressing up in seaweed as
a means of camouflaging themselves? Yes.
..and delve into our very own deep sea coral reefs.
This is the most important deep sea coral, I think, in the whole world,
and this is just off of Scotland.
So, dip into our UK waters
and see them like you've never seen them before.
BOTH: Welcome to Blue Planet UK.
Hi and welcome back to Blue Planet UK.
Today we have come to south-east England.
My home patch, Gillian, I love it down here.
This Kent coast
is full of memories for me and here in Herne Bay I can remember playing
just on these sandy beaches here,
building castles and generally causing mayhem with my brothers.
This is so different from my home patch in Cornwall.
These huge flat expanses, the landscape is beautiful.
Just goes to show what a rich and varied coastline Britain has.
More about Kent in a minute
but let's take a look at what's in today's programme.
Out of sight is certainly not out of mind as we meet the people
digging deep into the Sidmouth fatberg.
This is the biggest one I've seen, it's probably about here.
Chris gets a snapshot of the UK's underwater wildlife when he meets
photographer Kirsty Andrews.
Hiding underneath those waves are just a whole cast of the most
amazing creatures.
Got one!
There's family fun as I take my nephews hunting for prehistoric
shark teeth.
That's a good one, isn't it?
And the Blue Planet Live team listen closely as they go in search
of sperm whales.
Up there we've got Margate and behind me is Whitstable,
and Herne Bay was really put on the map when the Victorians
decided that sea bathing was going to be their new hobby.
Steve, did you know that this isn't the original pier?
The first one was built in 1831. That's my fun fact for the day.
I'm sure you knew that... Oh, it's a good fact.
It was made of wood and it quite literally fell apart.
The second pier they decided wasn't prestige enough for the town.
And the third pier was one of the biggest in its day.
And that's the remnants of it just there, over our shoulder.
There's a lot of people, in fact, that would like to see it rebuilt.
Herne Bay and the whole Kent coastline, in fact,
isn't just valuable for its holiday heritage.
The cliffs and the beaches here are also rich in marine life.
On the Kent coastline you can find towering chalk cliffs,
glistening mudflats,
and creeks winding through the salt marsh.
Its shallow seas are home to everything from seals to starfish.
The coastline of Kent has changed dramatically over the millennia.
Reculver was once a village, now just the church is left, teetering
dangerously close to the waves.
Steve, what a stunning place to have grown up.
I can see why you love it so much.
Of course I did! Playing up here with my brothers and then learning
so much about the wildlife.
Just behind us here you've got the waders and they're attracted here
because there's so much of the flat seabed exposed as the tide goes out.
It's not just great for the birds.
You've also got seals here.
Common and grey but, of course, the most grey seals are right
up round the coast in Norfolk.
Well, grey seals are actually, globally, quite a rare species,
but the UK has almost half the world's grey seal population
so it makes them a species of special responsibility
in this country.
Now, they are marine mammals, but they are bound to the land.
That's because they have to come ashore once a year to breed
in the winter, and when they do that's when they're really
vulnerable to disturbance.
But a few years ago I got to go swimming with grey seals on
the Isles of Scilly and I got to see them in their environment
on their terms.
What an incredible experience!
To have that moment of connection with a wild animal is just...
It's just unforgettable.
But there's something even more special.
When I dive I can hold my breath for about just under a minute.
A seal's average dive is ten minutes.
The record dive is 32 minutes
and that seal went down to a depth of 200 metres,
which is absolutely incredible.
Ah!
To say that was amazing is an understatement.
Now, when seals dive, or when I dive even, the same three things happen.
The heartbeat drops,
the blood is shunted from the limbs to the vital organs,
the heart, the lungs, the brain...
..and the lungs fill with fluid
as you start to dive deeper,
and this stops the lungs from collapsing.
All of this is a way to maximise the oxygen that's taken on board
at the beginning of the dive.
And what's really cool, in my opinion,
is that it's all triggered
when the face comes into contact with cold water.
I think that's absolutely incredible,
and I love that we share this with these beautiful creatures.
Gillian, they are so inquisitive, they're coming right up to you.
It was an amazing experience,
but you've got to remember they were wild animals
and I was swimming with them in their environment,
so they could choose how close they wanted to come to me.
But it's when you're on land
you've really got to give them that respectful distance.
Do you know, there's so much to celebrate about the UK coastline,
but for every amazing story,
there's so much that can still be done.
Well, absolutely.
I mean, we now know how much care we need to take about what we put
in the ocean as well as what we take out of it, and generations of waste
can cause a real marine disaster.
Yeah, they certainly can!
I mean, have you got any idea what a fatberg is?
If you don't, let me explain. OK, this isn't nice.
So, it's really... In the sewers,
all the congealed fats and greases that mix together with, maybe,
discarded wet wipes, other sanitary products.
It's not nice, but when I heard about one down in Devon,
I had to go and find out what it was.
Sidmouth,
a coastal town proud of its beaches and the quality of its sea,
rated as excellent for bathing.
But under the seafront, there's a growing problem that you may
remember hitting the headlines last year...
A giant fatberg as big as a Boeing 747,
or six double-decker buses,
has been discovered blocking a sewer in a seaside town.
Lurking beneath the town, a 21st-century reality.
It's the biggest one I've seen.
It's probably about here.
Charlie found the fatberg
when he was inspecting the sewers with his crew.
Andrew Roantree from South West Water
is at the heart of the work
to remove the fatberg before the busy tourist season
starts this summer.
What sort of monster are we talking about? Well, this one,
when they first went down, they estimated it was about 64 metres
long... Wow. So, it's sort of six double-decker buses size.
Wow. So it is a big...a big lump.
To me, I find it quite surprising that a place as rural as Sidmouth
has got such a big problem underneath it.
Yeah, that has come as a bit of a surprise to us.
In the south-west, most of our sewerage system
is relatively smaller.
We don't have a lot of big, urban environments.
This sewer where the fatberg has been found
was a historic holding tank,
and effectively it was a tidal release mechanism -
raw sewage discharged to sea -
based upon which direction the tide was going. Wow.
People have poured away hot fats down their kitchen sink,
and that becomes the glue that sticks together
other stuff down in the sewer.
And over the last few years,
we've particularly noticed that that other stuff tends to be wet wipes.
Wet wipes really should not go down the toilet at all.
They just don't break down like toilet paper does.
It's crazy to think that we're in an area
that is really quite beautiful.
It's naturally wonderful, and to think that just here,
there's a 64m problem, completely man-made...
Victorians would flush their waste straight out to sea, thinking
that the ocean was large enough to dilute it all.
They would quite literally paddle next to their own waste.
Historically, this practice continued in the UK for decades.
It took until 2002 for the waste here to be routed through a new
sewage works, cleaning the water and killing bacteria.
Nowadays, it seems like South West Water put in huge efforts
to preserve the quality of our seas.
But removing this fatberg is no small scale operation.
Protective breathing apparatus has to be worn at all times
when approaching the fatberg.
The gases are so concentrated that any spark could cause an explosion.
Samples from the fatberg are taken to Exeter University where John Love
and Nicky Cunningham are ready to get, well, stuck in!
Fatbergs can potentially be hazardous to the environment
because, for instance,
micro plastics have recently been
banned in face creams.
But it is possible that the fatberg
itself has actually accumulated micro plastics over the years
and can release those almost like a slow-release pollutant.
And then that would go to the sea,
that would enter the food chain, potentially.
And so while we think that we may have stopped the source of
pollution, actually, because there is a reservoir there, we might not
see the effects for quite some time.
John and Nicky superheat the sample,
killing any bacteria and melting the fat to reveal its dirty secrets.
Ah! Wow!
You can see that there is a lot of liquid in there.
But, look, we've already got...
..some really gross panty liners.
Yuck!
So, we're going to... We're going to leave that there.
And we'll just dig our way through it.
That looks like a wet wipe. Yep.
What's interesting about this is you can actually see it
solidifying on my gloves.
So even if it's liquid when it's poured down the sink,
it really won't take very long before it hardens
and solidifies in the sewer.
It's like the world's least enjoyable lucky dip, isn't it?!
It's funny!
THEY LAUGH
It's by understanding the make-up of the fatberg
that new methods to prevent them growing in the first place
can be developed.
The water industry will say very, very strongly that there are
products out there that people believe they can dispose of
by flushing them away, and actually they can't.
This is a...
We don't know what that is. Cotton bud?
A cotton bud stick, yeah.
Whoa! Thank goodness!
Thank goodness for the screen!
The dissection all has to take place
behind a ventilated protective barrier.
If you are wondering what it's smelling like... Ugh!
It's not good, is it?
It's awful.
Absolutely awful.
And here are the main culprits...
Sanitary products and wet wipes.
There you go. So those are our treasures.
All in a day's work.
With so much work going on behind the scenes and under our feet
to conserve our coastline, we all need to do our part.
Unfortunately, the Sidmouth fatberg shows that it's not just what we put
in our bins that creates the plastic problem but also what we flush
down our loos. And we need to act responsibly, now and in the future,
because a fatberg future is not one I relish.
It's a startling statistic to know that three quarters of all the fat
and grease in our sewers comes from our very own homes.
Putting it in the bin really can make a difference.
But bad news stories can be turned around, as Gillian found out.
My very first film for Springwatch was on my home patch
of Cornwall in 2016.
Basking sharks...
Seal colonies...
Dolphins...
We tend to be more impressed with the big things, the big animals.
And, of course, they're impressive,
but if you take your time
and you take the trouble
to investigate the small things,
the little things, the Lilliputian
world as I like to call it,
a whole new world opens up.
There's a tiny creature that has recently been discovered not far
from here that tells a huge story.
What's exciting about this story is that you don't have to travel
very far to some exotic, far-flung place.
This tiny creature was discovered on a very unassuming beach
in the middle of Falmouth town.
It's the sort of place that you rock up to with your deck chairs
and your windbreak, grab a crab sandwich and have an ice cream.
This is where a group of volunteers made a find that I think is
really exciting.
What I'm looking for is a rock pool
where there's lots of hermit crabs.
Right, let's have a look in here.
No sign of our little fella.
OK, there we go.
That's a common hermit crab in there. I don't know if you can see
that, its little claws poking out.
That's what I'm after, but this isn't the right species.
Just pop them back in.
Hermit crabs are a type of crab that make use of empty shells
that are found all over the beaches.
They're incredible animals with bags of personality, but the particular
species of hermit crab that I'm looking for
is really not easy to find.
Ha! SHE LAUGHS
Found him!
That is Clibanarius erythropus,
"soldier clad in mail with red legs",
and this one is being really obliging.
Can you see that it's come right out of the shell?
And you can get a really clear view of its red legs.
And what's remarkable about this is
both its claws are the same size.
What's common among most hermit crabs is one claw is larger,
so that's how you can be sure that you're looking at a clibanarius.
It doesn't have a common name yet.
So, these little guys were found in Cornwall
a long time ago.
This is actually the northern limit of their range.
They're found in Europe as well,
but in the 1960s, there was a massive oil spill,
the Torrey Canyon oil spill.
The clean-up effort involved the use of lots of toxic dispersants
that cleaned up the oil,
but also wiped out a lot of invertebrate life.
And our tiny hermit crab officially
became extinct from UK shores.
That was until it miraculously reappeared on this very beach.
This is one of the things that I love about the little things
in life, the fact that these animals have arrived back on these shores
after what was, at its time,
one of the worst environmental disasters recorded.
It's an indicator that the marine life along these shores
may finally have recovered.
I'd love to think that they're here to stay.
Well, that little survivor went on to be called St Piran's crab
by a popular audience vote on Springwatch.
St Piran being the 5th-century Cornish abbot and saint.
Joining me today is Lauren Eyles
from the Marine Conservation Society.
That was the biggest man-made disaster of its time.
What are the challenges facing our oceans today?
There are so many challenges.
I mean, plastic and litter is kind of the obvious one,
and so many of us are aware about it at the moment,
but it's not just plastic and litter.
What we need to see as well are more but also well-managed areas
that protect habitats and species,
so all the amazing things we get here in UK oceans, and there are
some incredible things. And we need to see those areas protected.
Why do you think plastic pollution has caught the public's imagination?
A real light has been switched on for so many, and particularly
after so many did watch Blue Planet II,
we really witnessed that
in terms of mass participation and concern for marine litter
where we saw hundreds of people turn out on beaches across the UK.
You know, the question I often get asked is, can these beach cleans
really make a difference?
We involve people in science.
Our work is all about citizen science,
and it's the data that we collect which is absolutely key
to the health of the marine environment.
At the Marine Conservation Society,
we use that information, that data,
to really bring about change.
So, we've used it to inform all of the plastic bag levees,
to encourage better labelling of wet wipe products and also a ban
on microbeads in the UK.
So, it's hugely important to collect the information which then gives us
the evidence to really change the situation around.
So, when you go down to the beach, of course, enjoy the wildlife, enjoy
the coastline, but help by picking up some litter or, like Steve
did with his nephews, look out for some ancient life.
I grew up on the on the Isle of Sheppey, and Minster was where I
lived - this is my back garden.
This is where I spent my summer days, up and down the coast,
in the sea, through the rock pools,
and I love being in this environment, and coming back here
is almost reliving childhood memories.
This coastline is part of the London clay formation dating back
around 50 million years.
Once, it was a lush forest.
Nowadays, the cliffs hold secrets of days gone by.
This is what we're after today,
shark's teeth, and they vary in size.
This is quite a big one that I found here,
and I can remember finding this one as a kid.
It's got a lot of history to it.
I can't wait now to be taking my nephews out,
and hopefully we'll get a few today.
Fossil hunting is a bit of a family tradition,
and today I've got the whole Brown clan out with me.
My nephews...
Wow! Look at this.
My two brothers...
This is just brotherly competition.
..and myself.
The sea washes fossils out of the clay here like a giant sieve,
and they can be found by anyone that's willing to search for them.
You never know what you're going to get here, which makes looking
for fossils all the more exciting.
Got one!
Each and every tide unlocks even more secrets,
ready for keen eyes to find.
Everything in this life at the moment is all about it
being instantaneous and getting instant gratification,
but here you've got to take your time, you've got to be patient,
and then when you find the teeth, it all makes it worthwhile.
They're all enjoying it,
they're all living in the moment and not rushing.
And these are the sort of things that being outside can do for you.
In actual fact, you found them twice up here before.
What do you enjoy about looking for sharks' teeth?
Finding them! Finding them...
STEVE LAUGHS
Well, I suppose that's the whole point, isn't it?
I used to enjoy coming to the beach with my family when I was younger,
and it's just nice to be able to bring my family here now,
my two young boys, and I just hope that they can enjoy it as much
as I did when I was growing up.
Fossils could be found in many places in the UK,
from the Jurassic Coast in Dorset to the Isle of Skye in Scotland.
But even if your beach isn't famed for its prehistoric treasures,
there are still secret worlds waiting to be discovered.
Rock pools provide havens for marine life,
hiding and waiting for the tide to turn.
And as it does, here on Minster beach,
it's time to head home for the day.
Let's have a look.
You've found another one!
That's a good one, isn't it?
So, do you prefer playing on your computer
or being out and looking for sharks' teeth?
Er, looking for sharks' teeth.
Yeah, and how many did you find today? Eight.
And how many did your dad find? One.
That's good, isn't it? You win again.
Finding sharks' teeth, whether you're 33 years old or 13 years old,
is fun.
You're out here and it's the history and the imagination,
knowing that what you've got is a fossilised tooth
that's millions of years old, and to be down on the beach
finding your own pieces of prehistoric history...
What kid wouldn't enjoy that?
Steve, that looked like such fun.
What a great thing to do with kids.
Yeah, I'm still grinning from it now. They love it,
and I used to love it when I was a kid.
And the thing is that Herne Bay itself is a huge place for going out
and collecting fossilised sharks' teeth.
Who would have thought that a Kent beach
would have so many million years' worth of history?
Well, back in the day, this place would have had a climate
more like what Spain is today,
and it would have been a rich habitat
for mammals, birds, insects, and of course marine life.
So, Steve, what are your top tips for fossil hunting here?
Well, you know, the thing is, where we're actually standing now,
the sharks would have been swimming over,
and so these sharks, they're extinct now,
but take a look, this is their teeth.
These are fossils you found here? Yeah!
Me and my nephews and my brothers have found these.
How cool is that?
And you can tell so much, can't you, about the sharks?
And when you're looking for them, the biggest tip I've got for you
is to look amongst the shingle the same size as the teeth.
They all wash up together. If the shingle's going to wash up,
the sharks' teeth will wash up with it.
And that is the first thing you've got to do.
Once you've got your eye in and you spot one,
it's much easier to then start finding others,
but finding your first one is the tricky bit.
Must be so exciting, though. Yeah.
Before Chris Packham left for Mexico for Blue Planet Live,
he went to meet a British photographer
who wants to show that British seas
are just as exciting as anywhere else on Earth.
I've come to meet a lawyer by day but a diver by passion.
Kirsty Andrews is also a keen marine photographer who fools fans
of her photographs into thinking that she travels the world
because her subjects look so exotic.
We took some of Kirsty's photographs out on the streets
to see whether people could guess where they were taken.
Fish!
Fish. Fish, yes. Fish.
A Hawaiian fish?
Somewhere round there.
I'm wondering if it is more over, like, the Caribbean way or, like,
the Galapagos or something.
Somewhere off Australia.
The Pacific or the Indian Ocean.
Tropical waters because it's a scuba diver
and it's coral reef and it's colourful.
Luminescent snail,
let's go for that, sounds like a species. Sounds official!
And in the Atlantic Ocean.
I reckon it's a trick question
and they're all off the coast of Britain, the UK.
These are all off our coast? Really?
Well, yeah, no, don't believe it.
I don't think the UK is tropical, mate,
especially with the weather today!
Kirsty, what is it that makes you want to immerse yourself
in this leaden froth?
It doesn't look very appealing today, it's true,
but then it also looks really enticing to me.
I mean, what is in there, you know, hiding underneath those waves,
is just a whole cast of just the most amazing creatures.
I started off just taking a little camera in my pocket,
see what I could see, and then it's gradually become a bit obsessional,
that I just love to, really....
I like the technical challenge of photography,
as well as just getting that much closer to the wildlife and capturing
that behaviour, just to create that perfect shot,
which I haven't quite got yet.
Well, let's have a look. Yeah, sure.
I'll need my glasses.
This was taken in Scotland.
These are sponges and anemones and corals, are they?
That's right.
And it is extraordinarily colourful.
It's like a scene from Finding Nemo, isn't it?
Except you're short of a clownfish and you've got a diver
giving it perspective there.
That's right!
Well, we don't have clownfish in the UK, but we do have corkwing wrasse.
Goodness, look at that.
It really does look like it could be on a tropical reef. It does indeed.
This is the male, often the male is more colourful than the female.
Amazing, what a stunning animal.
So, this is a bit of a cheeky one, really.
I was coming back from a dive and I spotted this just bit of rubbish.
On closer look,
I saw it had a little Scottish lobster living in it.
Looks a bit feisty! It does.
It's come out to say, you know, well, I can't do a Scottish accent
and it's probably best that I don't, actually,
but we can imagine what it's saying, it's come out of its house... Yeah.
And you do see this, you see wildlife making a home out of things
on the seabed.
That's not necessarily what you want to see, but there's a different
message that you can use your photography for, as well.
I do try and get an eye-catching composition.
I like a face-on kind of shot to really grab attention.
This is a greater pipefish. Oh, yes.
Snout pointing forwards...
I like the symmetry of that one, I have to say.
The fish is not spectacular.
Maybe a bit more spectacular for you. Here's another symmetry shot.
Yeah, now that I like a lot.
I mean, obviously the tentacles aren't exactly symmetrical
but I'm being niggly.
It's a cuttlefish with its tentacles raised, is it?
That's right, yeah.
The textures and colours are absolutely fantastic.
And that's all the chromatophores in the cuttlefish that it uses
to give the display.
And in this shot, it's giving me a threat display,
it's trying to warn me off. Is that right?
I like the photos.
I suppose, if there's a limitation,
it's the fact that none of them are backlit, and I love shooting
into the light, you know, putting that rim of light around things
and using it to create effects going into the camera.
I suppose you've got here... Yeah, OK, there's a natural one
using the sunlight there. That's beautiful.
Well, there we are. You've finished on a high because that's my
favourite photograph that you've shown me.
The seal is perfectly positioned in that white foaming water,
and you've got that remarkable
silvery molten texture above it.
That's my favourite, that and the cuttlefish are my favourites.
But in terms of what you want... We've always got ambitions of what
we imagine we want to do next.
What is it for you? Oh, well, keep on improving, I suppose.
I've never had that perfect,
peaceful moment with a basking shark.
I'd like to just be there and have one swim up to me,
mouth open, feeding,
and be able to capture that.
Bit of backlight underneath.
Silhouetted against with all those rays coming down through the water.
I'll think of you and I'll try and do something like that.
Ah! I'm dreaming of it already!
Across the country, there are many conservation success stories
that give us cause for celebration,
and one such story is of the white-tailed eagles of Mull.
Last year, young natural history film-maker Tom Campbell captured
this tale that he aptly named Where Eagles Dare.
The Isle of Mull, off the west coast of Scotland,
is a rugged and beautiful landscape.
It's home to RSPB Officer Dave Sexton...
..and the UK's largest bird of prey.
The white-tailed sea eagle was once the most common eagle in the UK
but was hunted to extinction a century ago, mainly due
to its reputation for killing livestock.
In the 1980s, the birds were reintroduced to Scotland.
Initially, to the Isle of Rum,
before eventually settling on neighbouring Mull.
This cemented Dave's future on the island, too.
We were driving back along the sea loch and we knew the sea eagles
might be around. There'd been one or two sightings from Mull.
Suddenly, as we were driving back, there was this massive bird flapping
hard across, quite low over the water, over the sea loch.
And we leapt out of the vehicle and there was a sea eagle.
And it was just an incredible experience. And that's what
really inspired me to get involved in this project
to bring sea eagles back to Scotland.
I've made a nuisance of myself, really, by pestering the guys
in species protection department, and I was sent on a secret mission
to protect the only pair of nesting sea eagles in Britain.
Dave is travelling deep into the heart of Tiroran Forest
with a team from the RSPB to visit a very special pair of eagles,
Fingal and Iona.
We know this pair really well.
The female was hatched in 1998.
She's a Scottish bird from north-west Scotland.
The male here is actually a Norwegian import from 1997.
So they're good mature birds now
and have been raising chicks for many years.
What we're doing today is trying to ring the chick of this pair.
The ringing process is really important because it helps us
monitor the overall population.
Justin and Lewis are now going to be measuring, getting the ring on.
It's a British Trust for Ornithology ring on one leg
and a colour ring with big letters on another leg,
that we'll be able to read, hopefully, from a distance.
They begin the long and dangerous climb to the eyrie.
They must work fast so the family aren't disturbed for long.
SEA EAGLE CRIES
Somewhat bemused, perhaps, the eaglet allows the work to continue
and the team get away from the nest as soon as possible,
leaving the chick in peace.
As white-tailed sea eagles have re-established
their territories on Mull,
the islanders have found benefits to living alongside
this impressive predator.
Sea eagles benefit the community because a lot of people come here
on their holidays specifically to see the eagles, and it's widely
regarded as the best place, certainly in the United Kingdom,
to come and view sea eagles.
All that generates trade for the island.
Local skipper Martin Keivers has found that people will flock
for miles to get a glimpse of this bird's
impressive hunting display.
It seems that the sea eagles are going from strength to strength
here on Mull,
and Dave has been part of their story since the very beginning...
..from witnessing the first chicks fledging
to seeing numbers steadily grow.
Here, on the wild west coast of Scotland,
eagles are thriving once more.
Now it's time to go behind the scenes of Blue Planet Live.
One of the species that they're filming are sperm whales,
and you may remember they had a massive impact on the audience
in Blue Planet II when they had cameras put on them.
One of the challenges facing the team this time was trying to get
a camera to record sperm whale behaviour
at an even greater depth.
But finding a sperm whale is a challenge all of its own.
The team are attempting to film sperm whales who spend
much of their time under water but surface occasionally for air.
Sperm whales spend 45 minutes out of every hour in the darkness
of the deep ocean,
so just coming out here and looking for them would be really tricky.
We take advantage of the fact that they make sound the whole time
they're under water to keep up with them.
I'm using an underwater microphone to track the whales.
So, when they're hunting for squid, they make echolocation like bats do
in the night-time sky. We can hear that with this,
and this will actually tell us
which direction the clicks are loudest,
so we can follow them and stay with the family.
We can hear a few kilometres away.
The echolocation that the sperm whales make is really loud
and so we can usually hear them before we see them.
So we'll get closer and then we'll start seeing blows
and start working today.
Blows are plumes of spray that the whales make when breathing
at the surface.
In a calm, clear expanse of water, they're easy to spot.
And, sure enough, the team have seen one.
The engines are cut and they are joined
by the underwater camera team.
Cameraman Mark Sharman prepares his underwater equipment.
Sperm whales are incredible animals to film.
Just their sheer size alone is really awesome,
and just to be that close to something that huge
is an unbelievable feeling.
There's not many things you can do in the world that makes you feel
so small and insignificant.
Just go straight down. OK.
Camera ready, Mark enters the water to approach the sperm whale.
The wind is starting to pick up onshore.
We're getting a bit a chop, and it could end up being a bit
difficult to keep an eye on him,
so it's something that we really have to watch for.
Mark manages to get some footage, but not what he was hoping for.
So, there were two whales at the surface -
the calf Corkscrew and Knife, the mother.
Corkscrew turned on her back,
and it looked like she must have been looking up at me
as I was at the surface. So a very unusual perspective,
to see an upside-down swimming sperm whale about ten metres below me.
But, yeah, that's what I saw.
But as they didn't do a deep dive, then I'm pretty sure
they're going to be surfacing in the next five...
..15 minutes or so.
Mark re-enters the water to get even more shots
of these magnificent creatures.
Here you go. Yeah.
How was that? It was amazing.
Yeah, finally got the shot.
You guys dropped me in a great position.
I was able to get in front of her, and she was cruising right,
so I had a good five metres of her coming towards me,
which was a fantastic angle to get,
and then she came right past me. She didn't notice me.
And then I just saw her eyes just open like that... Wow.
..as I'm passing. It was unbelievable.
What an encounter there for Mark! Magic. Absolute magic.
Well, that is it from us today.
Don't forget to join the Blue Planet Live team tonight
for more wondrous stories from the oceans of BBC One.
Whilst they're bringing you the stories
from the world's waters, we'll be back same time tomorrow
for more from this great UK coastline.
Next time on Blue Planet UK....
I love science experiments.
..I get in a spin when I find out how washing your clothes can result
in plastic pollution.
We're finding a lot of fibres in the marine environment.
We're finding them in the deep sea
and we're finding them in marine creatures as well.
We learn how a national dish has been bad for our fish.
Who would have thought that underneath that lovely crispy batter
could be a kind of shark?
We find out about the crustaceans making a comeback along our coast.
And Chris discusses a fashion-conscious crab
when he meets biologist Paul Naylor.
They're dressing up in seaweed as a means of camouflaging themselves?