0:00:29 > 0:00:32The oceans, seemingly limitless,
0:00:32 > 0:00:37invoke in us a sense of awe and wonder and also, sometimes, fear.
0:00:37 > 0:00:43They cover 70% of the surface of our planet and yet they are still
0:00:43 > 0:00:45the least explored.
0:00:47 > 0:00:51Hidden beneath the waves, right beneath my feet,
0:00:51 > 0:00:54there are creatures beyond our imagination.
0:01:09 > 0:01:13With revolutionary technology, we can enter new worlds...
0:01:19 > 0:01:22..and shine a light on behaviours in ways that were impossible
0:01:22 > 0:01:24just a generation ago.
0:01:28 > 0:01:31We've also recognised an uncomfortable fact -
0:01:31 > 0:01:34the health of our oceans is under threat.
0:01:34 > 0:01:38They are changing at a faster rate than ever before in human history.
0:01:44 > 0:01:49Never has there been a more crucial time to reveal what is going on
0:01:49 > 0:01:51beneath the surface of the seas.
0:02:06 > 0:02:09In this first episode...
0:02:10 > 0:02:13..we will journey across the globe,
0:02:13 > 0:02:16from the warm waters of the tropics...
0:02:18 > 0:02:21..to the coldest around the poles...
0:02:25 > 0:02:29..to bring us a new understanding of life
0:02:29 > 0:02:30beneath the waves.
0:02:37 > 0:02:40This is Blue Planet II.
0:03:38 > 0:03:40The surface of the ocean
0:03:40 > 0:03:43conceals the many creatures that live beneath.
0:03:55 > 0:03:58But not all.
0:04:01 > 0:04:03Bottlenose dolphins.
0:04:06 > 0:04:08They are extremely intelligent.
0:04:19 > 0:04:21And with this intelligence comes playfulness.
0:04:29 > 0:04:31They surf.
0:04:32 > 0:04:34And, as far as we can tell,
0:04:34 > 0:04:37they do so for the sheer joy of it.
0:05:05 > 0:05:09But to properly appreciate their true character,
0:05:09 > 0:05:13you have to travel with them into their world.
0:05:13 > 0:05:15DOLPHINS WHISTLE AND CLICK
0:05:27 > 0:05:29A pod of bottlenose dolphins
0:05:29 > 0:05:32is visiting a coral reef in the Red Sea.
0:05:34 > 0:05:38For the youngsters, there are things to be learned here.
0:05:38 > 0:05:40DOLPHINS WHISTLE AND CLICK
0:05:47 > 0:05:52The adults lead a calf to a particular bush-like coral,
0:05:52 > 0:05:54called a gorgonian.
0:06:08 > 0:06:11And here the adults behave rather strangely.
0:06:17 > 0:06:21They deliberately rub themselves through the fronds.
0:06:34 > 0:06:37Their calf seems reluctant to do so.
0:06:50 > 0:06:51By watching his elders,
0:06:51 > 0:06:55he may be realising that this is something he ought to do.
0:07:02 > 0:07:04Gorgonian fronds, in fact,
0:07:04 > 0:07:08are covered with a mucus that can have anti-inflammatory
0:07:08 > 0:07:11and antimicrobial properties.
0:07:15 > 0:07:18So maybe the adult dolphins are doing this
0:07:18 > 0:07:20to protect themselves from infection.
0:07:30 > 0:07:35The dolphins' intimate knowledge of the reef...
0:07:35 > 0:07:39is spurring us to search for new medicines here, too.
0:07:49 > 0:07:55Tropical coral reefs occupy only a tenth of 1% of the ocean floor.
0:07:57 > 0:08:02But their shallow warm waters and stable year-round conditions support
0:08:02 > 0:08:05some of the most crowded and varied communities
0:08:05 > 0:08:08to be found anywhere in the oceans.
0:08:11 > 0:08:15And there are new discoveries to be made on every one of them.
0:08:36 > 0:08:41One creature on Australia's Great Barrier Reef is challenging our
0:08:41 > 0:08:45understanding of fish intelligence.
0:08:45 > 0:08:47A tuskfish.
0:08:47 > 0:08:49And you can see why it gets its name.
0:08:54 > 0:08:58He does something few would have believed a fish could do.
0:09:05 > 0:09:09Every morning, he travels to the edge of the reef.
0:09:23 > 0:09:26He's searching for something special to eat
0:09:26 > 0:09:28amongst the coral, rubble and sand.
0:09:39 > 0:09:41Here's one.
0:09:43 > 0:09:44A small clam.
0:09:52 > 0:09:55But how to crack it open and get to the meat?
0:10:07 > 0:10:11He takes it all the way back to his special kitchen...
0:10:20 > 0:10:24..a bowl-shaped coral that has a particular bump
0:10:24 > 0:10:27on the inside that he always uses.
0:10:44 > 0:10:48It's not easy if you have no hands.
0:10:56 > 0:10:59Whoops, there he goes again.
0:11:04 > 0:11:06But he's got great determination...
0:11:12 > 0:11:14..and surprising accuracy.
0:11:34 > 0:11:35At last!
0:11:38 > 0:11:41So here is a fish that uses tools.
0:11:43 > 0:11:48Some fish are much cleverer than you might suppose.
0:12:05 > 0:12:08The density of the animals on tropical reefs
0:12:08 > 0:12:11makes competition inevitable and extreme.
0:12:12 > 0:12:16Not only for those that live within the reefs...
0:12:17 > 0:12:19..but for the birds that fly above them.
0:12:23 > 0:12:25During the dry season,
0:12:25 > 0:12:29over half a million terns crowd onto this remote atoll
0:12:29 > 0:12:31in the Indian Ocean.
0:12:31 > 0:12:33TERNS CHIRP
0:12:38 > 0:12:41Their chicks are still in their dark juvenile plumage.
0:12:47 > 0:12:48They vary in age.
0:12:57 > 0:13:00Whilst the more advanced chicks take to the air...
0:13:08 > 0:13:10..others aren't quite ready yet.
0:13:30 > 0:13:35Those just starting to learn to fly use the shallow lagoon that occupies
0:13:35 > 0:13:38the centre of the atoll as their training ground.
0:13:41 > 0:13:44It's difficult for some of them to stay aloft for long.
0:14:08 > 0:14:10Giant trevallies.
0:14:23 > 0:14:27Usually they are solitary hunters.
0:14:27 > 0:14:30But about 50 of them have come here from neighbouring reefs,
0:14:30 > 0:14:34attracted by this abundance of potential prey.
0:14:42 > 0:14:47The fledglings stay out of the water if they can.
0:14:47 > 0:14:49They even drink on the wing.
0:15:07 > 0:15:10If the trevally are to catch one now,
0:15:10 > 0:15:12they have to up their game.
0:15:22 > 0:15:25So there is a fish here that, amazingly,
0:15:25 > 0:15:29has a brain capable of calculating the airspeed,
0:15:29 > 0:15:32altitude and trajectory of a bird.
0:16:04 > 0:16:08The time comes when every fledgling has to take to the air
0:16:08 > 0:16:10and collect food for itself.
0:16:34 > 0:16:37Their parents lead them to the training grounds.
0:18:12 > 0:18:14If they are to survive,
0:18:14 > 0:18:16they must learn quickly.
0:18:25 > 0:18:28After a month of practising over the lagoon,
0:18:28 > 0:18:30the youngsters start to leave
0:18:30 > 0:18:33and take their chances out over the open sea.
0:18:40 > 0:18:46The oceans hold 97% of all the water in the world.
0:18:48 > 0:18:53As the sun warms their surface, water evaporates.
0:18:53 > 0:18:57The vapour rises into the sky until it cools and condenses
0:18:57 > 0:18:59into towering clouds.
0:19:01 > 0:19:05And they generate huge storms.
0:19:08 > 0:19:13The spin of the Earth deflects these storms north and south
0:19:13 > 0:19:15into cooler latitudes.
0:19:24 > 0:19:26As they travel across the sea,
0:19:26 > 0:19:29storm-driven winds create huge swells.
0:19:42 > 0:19:46When the swells reach shallower water,
0:19:46 > 0:19:48they rise into gigantic waves.
0:20:06 > 0:20:10In its lifetime, a large storm can release energy
0:20:10 > 0:20:14that is the equivalent of 10,000 nuclear bombs.
0:20:39 > 0:20:42These are the seasonal seas.
0:20:45 > 0:20:50And when they warm in spring, they can suddenly explode with life.
0:21:05 > 0:21:09Mobula rays have gathered in Mexico's Sea of Cortez
0:21:09 > 0:21:10in vast numbers.
0:21:18 > 0:21:20Why do they leap?
0:21:22 > 0:21:24Is it to tell others that they're here?
0:21:28 > 0:21:29No-one knows.
0:21:33 > 0:21:35They feed mostly at night,
0:21:35 > 0:21:40for that is when vast swarms of plankton rise from the depths.
0:21:46 > 0:21:49The disturbance in the water stimulates many
0:21:49 > 0:21:52of the planktonic creatures to luminesce.
0:21:54 > 0:21:59Only now do we have the technology to record their faint glow.
0:22:08 > 0:22:11The feasting rays swim through them,
0:22:11 > 0:22:15creating an extraordinary ballet of life and death.
0:23:03 > 0:23:08The richness of these waters is based on microscopic plants -
0:23:08 > 0:23:14phytoplankton - which bloom on such a massive scale they benefit us all.
0:23:17 > 0:23:21They, together with seaweeds and seagrasses,
0:23:21 > 0:23:26produce as much oxygen as all the forests and grassy plains on land.
0:23:38 > 0:23:42Every spring, off New Zealand, the seasonal bounty
0:23:42 > 0:23:44draws in rare visitors...
0:23:53 > 0:23:54..false killer whales.
0:23:58 > 0:24:00They are relatives of the orca,
0:24:00 > 0:24:03six metres long and weighing over a tonne.
0:24:12 > 0:24:15They appear to be searching for dolphins.
0:24:19 > 0:24:21And there are many in these coastal waters.
0:24:28 > 0:24:31DOLPHINS WHISTLE AND CLICK
0:24:31 > 0:24:34Here, bottlenose dolphins stick together,
0:24:34 > 0:24:37constantly chattering with whistles and clicks.
0:24:47 > 0:24:49Such a din carries for miles underwater.
0:24:56 > 0:24:58The false killers have detected them.
0:25:22 > 0:25:25Travelling at ten knots, the killers quickly close in on them.
0:25:43 > 0:25:47But then, something truly extraordinary happens.
0:25:53 > 0:25:59The dolphins turn, as if to greet their pursuers.
0:25:59 > 0:26:02DOLPHINS SQUEAK
0:26:07 > 0:26:09They seem to change their calls.
0:26:11 > 0:26:14Could it be that they are attempting to communicate?
0:26:24 > 0:26:28Scientists studying this annual encounter now think that
0:26:28 > 0:26:31individuals may recognise one another.
0:26:35 > 0:26:36Almost unbelievably,
0:26:36 > 0:26:40it seems that these different species appear to be old friends.
0:26:48 > 0:26:53Together they are gathering as one unified army, up to 1,000-strong.
0:27:01 > 0:27:05This formidable hunting party now harvests the riches
0:27:05 > 0:27:08that come with New Zealand's summer.
0:27:31 > 0:27:33All across the higher latitudes,
0:27:33 > 0:27:37seasonal seas flourish under the summer sun.
0:27:40 > 0:27:41Here in Alaska,
0:27:41 > 0:27:46sea otters lounge in the canopy of great submarine forests.
0:27:53 > 0:28:00Giant kelp, the biggest seaweed of all, is home to all kinds of life.
0:28:02 > 0:28:06On the forest floor, spiny sea urchins munch through the kelp.
0:28:08 > 0:28:13Elsewhere, there are continuously hungry sea cucumbers.
0:28:16 > 0:28:21And, in the tangled undergrowth, wonderfully camouflaged sea dragons.
0:28:32 > 0:28:36In the underwater forests of northern Japan,
0:28:36 > 0:28:38the residents of this sunken wreck
0:28:38 > 0:28:40are waiting for the summer temperatures
0:28:40 > 0:28:43to reach 16 degrees Celsius.
0:28:55 > 0:28:59That, for some, is the time for mating.
0:29:13 > 0:29:17A kind of giant wrasse called a kobudai.
0:29:23 > 0:29:24This is a male.
0:29:30 > 0:29:33And in female terms, he is particularly handsome.
0:29:41 > 0:29:45He's a metre long and weighs 15 kilos.
0:29:48 > 0:29:51Much larger than the diminutive female.
0:29:55 > 0:29:57And he is ready to breed.
0:30:01 > 0:30:04He attempts to mate with her -
0:30:04 > 0:30:06and with any of the other dozen or so females
0:30:06 > 0:30:10that live in his territory -
0:30:10 > 0:30:12whenever he gets the chance.
0:30:26 > 0:30:29But females from around ten years old
0:30:29 > 0:30:32take little notice of his advances.
0:31:00 > 0:31:05This is because when any large female reaches a critical body size,
0:31:05 > 0:31:08she can begin a dramatic transformation.
0:31:26 > 0:31:28Over just a few months,
0:31:28 > 0:31:32particular enzymes inside her body cease to work.
0:31:34 > 0:31:37And male hormones start to circulate.
0:31:42 > 0:31:45As time passes,
0:31:45 > 0:31:49her head expands and her chin gets longer.
0:31:52 > 0:31:56A she has changed into a he.
0:32:05 > 0:32:08And with this comes a change in temperament.
0:32:15 > 0:32:17The old male who ruled all the females here...
0:32:20 > 0:32:22..is challenged to a face-off.
0:32:29 > 0:32:34The more bulbous the head, the more it intimidates an opponent.
0:33:01 > 0:33:04The territory has a new ruler.
0:33:16 > 0:33:20Only the largest females transform themselves in this way.
0:33:26 > 0:33:30But the change enables them to have more mates,
0:33:30 > 0:33:33so they will have many more offspring carrying their genes.
0:33:40 > 0:33:42But a new male can't afford to be complacent.
0:33:45 > 0:33:49Inside the body of every kobudai female,
0:33:49 > 0:33:52there is a new male in waiting.
0:34:11 > 0:34:14The closer we travel towards the poles,
0:34:14 > 0:34:16the colder the seas become.
0:34:20 > 0:34:21Icebergs appear,
0:34:21 > 0:34:24huge slabs that have broken away
0:34:24 > 0:34:27from glaciers that are sliding into the sea.
0:34:28 > 0:34:31And then the surface starts to freeze.
0:34:42 > 0:34:45While the lights of the aurora play above,
0:34:45 > 0:34:47even in the depths of midwinter,
0:34:47 > 0:34:51there are a few places well north of the Arctic Circle
0:34:51 > 0:34:53that are still open.
0:35:04 > 0:35:09The fjords of northern Norway remain ice-free because a giant current,
0:35:09 > 0:35:13the Gulf Stream, flows up here from the south,
0:35:13 > 0:35:15bringing warmth all the way from the Caribbean.
0:35:20 > 0:35:24And every winter, billions of herring come here for shelter.
0:35:28 > 0:35:30And following them...
0:35:33 > 0:35:34..orca.
0:35:46 > 0:35:48There are up to 1,000 of them.
0:35:50 > 0:35:54It's possibly the greatest gathering of orca on the planet.
0:36:04 > 0:36:06The herring may be plentiful,
0:36:06 > 0:36:11but in these widening fjords they're not always easy to track down.
0:36:15 > 0:36:20These particular orca, however, are fish-hunting specialists.
0:36:30 > 0:36:31They work as a team,
0:36:31 > 0:36:35coordinating their approach by calling loudly to one another.
0:36:41 > 0:36:44They herd the herring into tighter and tighter shoals.
0:36:59 > 0:37:03They swim below them, trapping them against the surface of the sea.
0:37:12 > 0:37:15And now the orca deploy their special weapon.
0:37:21 > 0:37:25They beat their tails with such force that the shock waves
0:37:25 > 0:37:27stun the herring.
0:37:30 > 0:37:34And then the senseless victims are easily collected.
0:38:08 > 0:38:11But all this underwater noise attracts others.
0:38:19 > 0:38:21Humpback whales.
0:38:23 > 0:38:25They move in on the action.
0:38:34 > 0:38:38They approach the shoal from beneath and then lunge upwards...
0:38:44 > 0:38:48..gathering up to 100 kilos of herring in a single mouthful.
0:39:07 > 0:39:11The humpbacks are comparative newcomers.
0:39:11 > 0:39:14They only started coming here within the last decade.
0:39:25 > 0:39:28But these polar seas are so rich
0:39:28 > 0:39:31that there appears to be enough food for everyone.
0:39:53 > 0:39:56Nonetheless, few, if any,
0:39:56 > 0:40:00of these riches would be here were it not for the Gulf Stream.
0:40:09 > 0:40:14Ocean currents, in fact, are crucial to the wellbeing of our planet.
0:40:19 > 0:40:22They distribute the sun's heat towards the poles
0:40:22 > 0:40:26all the way from the equator,
0:40:26 > 0:40:30maintaining a climate favourable for life almost everywhere.
0:40:37 > 0:40:40From creating the weather to producing oxygen,
0:40:40 > 0:40:43the seas keep our world healthy.
0:40:52 > 0:40:56But there are now worrying signs that conditions in the oceans
0:40:56 > 0:41:01that have remained relatively stable for millennia are changing rapidly.
0:41:03 > 0:41:07Nowhere is this more evident than in the Arctic.
0:41:09 > 0:41:11Here in the past 30 years,
0:41:11 > 0:41:16the extent of the ice in summer has been reduced by 40%.
0:41:17 > 0:41:22This southern warming, most likely a consequence of human activity,
0:41:22 > 0:41:26is having a profound impact on its wildlife.
0:41:33 > 0:41:36Walruses are among those that are seriously affected.
0:41:46 > 0:41:50Every adult female needs to find a safe place
0:41:50 > 0:41:53where her 80-kilo pup can rest.
0:41:56 > 0:42:00The sea ice is retreating from much of the walruses' traditional range
0:42:00 > 0:42:03so they now have to haul out on dry land.
0:42:03 > 0:42:05WALRUSES GROWL
0:42:09 > 0:42:12But a herd of hundreds of quarrelsome mothers -
0:42:12 > 0:42:16some weighing almost a tonne - is not an ideal nursery.
0:42:25 > 0:42:29Walruses on land stick together for good reason.
0:42:31 > 0:42:33Polar bears.
0:42:37 > 0:42:41A full-grown male walrus is gigantic -
0:42:41 > 0:42:43too big for even a polar bear to tackle.
0:42:45 > 0:42:49So the bear is looking for a walrus baby.
0:42:55 > 0:42:58The scent of the bear spreads alarm through the colony.
0:43:05 > 0:43:08The walruses retreat into the sea.
0:43:26 > 0:43:29The bear knows it won't be able to catch them there.
0:43:39 > 0:43:42But she, too, has young ones to feed.
0:43:49 > 0:43:51What is a mother to do?
0:44:02 > 0:44:07A mother walrus still needs to find a place where her young can rest.
0:44:14 > 0:44:17A melting iceberg might do.
0:44:18 > 0:44:21But she is not the first to find this one.
0:44:29 > 0:44:31Suitable places are already taken.
0:45:05 > 0:45:07Other mothers don't want to share.
0:45:12 > 0:45:16They, too, need a patch of ice where they can protect their young.
0:45:22 > 0:45:26A desperate mother has no choice but to barge her way in.
0:45:28 > 0:45:30WALRUSES GROWL
0:45:50 > 0:45:54So this time, everyone loses.
0:46:18 > 0:46:22Finding the right place on these melting shores
0:46:22 > 0:46:24gets harder and harder.
0:46:59 > 0:47:04Solving these problems together helps create a bond so strong
0:47:04 > 0:47:07that the mother will stay in contact with her young
0:47:07 > 0:47:09for the rest of her life.
0:47:21 > 0:47:24But who knows now what their future will be?
0:47:38 > 0:47:41As we understand more about the complexity
0:47:41 > 0:47:45of the lives of sea creatures,
0:47:45 > 0:47:51so we begin to appreciate the fragility of their home,
0:47:51 > 0:47:53our blue planet.
0:48:29 > 0:48:32Blue Planet II has been four years in the making.
0:48:35 > 0:48:37The teams have explored every ocean,
0:48:37 > 0:48:42seeking extraordinary untold stories, many new to science.
0:48:49 > 0:48:53Bringing a new understanding of life beneath the waves.
0:49:04 > 0:49:08The latest diving technology, producing no bubbles or noise,
0:49:08 > 0:49:12has allowed our teams longer and closer encounters.
0:49:19 > 0:49:22To explore our final frontier, the deep,
0:49:22 > 0:49:26we have spent 1,000 hours in submersibles
0:49:26 > 0:49:29over half a mile below the surface.
0:49:33 > 0:49:36Innovative new camera technology makes it possible
0:49:36 > 0:49:39to film moments never seen before.
0:49:41 > 0:49:45Low-light cameras capture magical events almost invisible
0:49:45 > 0:49:47to the naked eye.
0:49:58 > 0:50:01Probe cameras give a completely fresh perspective
0:50:01 > 0:50:03into the lives of tiny creatures...
0:50:03 > 0:50:06Here it comes, here it comes.
0:50:06 > 0:50:11..while suction cameras take us on a giant's-eye view of the ocean.
0:50:18 > 0:50:22But the sea is an unpredictable and dangerous place to work.
0:50:27 > 0:50:31Nowhere more so than the so-called Wild Coast of South Africa...
0:50:34 > 0:50:36..home to surfing dolphins.
0:50:43 > 0:50:46The team's mission here is to ride alongside the dolphins
0:50:46 > 0:50:51and record their surfing behaviour in closer detail than ever before.
0:50:55 > 0:50:57These are treacherous seas,
0:50:57 > 0:51:01so the film crew enlist local professional surfers to guide them.
0:51:10 > 0:51:15But this year, the waves are bigger than anyone had anticipated.
0:51:17 > 0:51:20A daunting prospect for surf cameraman Chris Bryan.
0:51:22 > 0:51:24Yeah, I'm feeling pretty nervous.
0:51:25 > 0:51:27It's a big swell out there.
0:51:27 > 0:51:29Really big swell.
0:51:29 > 0:51:32There's 20ft waves out there and...
0:51:32 > 0:51:34..yeah, this will probably be the biggest seas
0:51:34 > 0:51:36I think I've ever been out in.
0:51:36 > 0:51:37No risks, no reward, I guess.
0:51:40 > 0:51:44Chris has a high-speed camera to shoot super-slow-motion action
0:51:44 > 0:51:45in the waves.
0:51:50 > 0:51:52The challenge is to get as close
0:51:52 > 0:51:54to the wave-riding dolphins as possible.
0:51:57 > 0:52:01The good news is that the dolphins have been spotted on the horizon.
0:52:07 > 0:52:11They said this was going to be the biggest swell of the year and, hey,
0:52:11 > 0:52:13I've never seen anything like this.
0:52:13 > 0:52:15This is much bigger than I had possibly imagined.
0:52:23 > 0:52:27In these waves, the only way to get out to the dolphins
0:52:27 > 0:52:28is with a Jet Ski.
0:52:30 > 0:52:32It's going to be enough of a challenge for them
0:52:32 > 0:52:33just to kind of weave their way out.
0:52:58 > 0:53:00At last, the driver's detailed knowledge
0:53:00 > 0:53:03gets them safely through the massive breakers.
0:53:06 > 0:53:08But the dolphins are nowhere to be seen...
0:53:12 > 0:53:15..leaving the crew to face the hair-raising task
0:53:15 > 0:53:16of getting back to shore.
0:53:31 > 0:53:33Go, go, go, go!
0:53:42 > 0:53:45Oh!
0:53:48 > 0:53:51- How was that? - That was pretty wild, yeah.
0:53:52 > 0:53:54The wave actually hit the back of the sled and I was like,
0:53:54 > 0:53:56"Go, go, get out of here, James. Get out of here."
0:53:56 > 0:53:58Hit a big bump and almost bounced off.
0:53:58 > 0:54:02I was trying to hold the camera and just rode out of there, but, yeah,
0:54:02 > 0:54:04it was hectic.
0:54:04 > 0:54:05Just another day at the office.
0:54:11 > 0:54:15The next day brings a sudden change in conditions.
0:54:19 > 0:54:22Plenty of dolphins
0:54:22 > 0:54:23but a calmer sea.
0:54:25 > 0:54:27A complete lack of any wave at all!
0:54:29 > 0:54:31They'll come, they'll come, they'll come!
0:54:35 > 0:54:36As so often in the ocean,
0:54:36 > 0:54:40if you know you're in the right place, you just need the patience
0:54:40 > 0:54:42to wait for the perfect moment.
0:54:49 > 0:54:55A week later and a storm is once again brewing off the Wild Coast,
0:54:55 > 0:54:56and surf is building.
0:54:56 > 0:54:59Kind of like a nervous excitement.
0:54:59 > 0:55:01The conditions are absolutely perfect, this is
0:55:01 > 0:55:04completely what we've been waiting for.
0:55:04 > 0:55:06And the dolphins seem to know it.
0:55:08 > 0:55:12But Chris is struggling to get a steady shot.
0:55:15 > 0:55:16How about that?
0:55:17 > 0:55:20Hello, gentlemen. It's tricky.
0:55:20 > 0:55:23A little tricky on the Jet Ski, just trying to get the right angle.
0:55:23 > 0:55:25So I'm going to have a go on the Zodiac
0:55:25 > 0:55:27and hopefully have better luck on that one.
0:55:39 > 0:55:42The inflatable boat gives Chris a larger,
0:55:42 > 0:55:44more stable filming platform.
0:55:47 > 0:55:52At last, he's in exactly the right place at exactly the right time.
0:55:57 > 0:55:59And the results are spectacular.
0:56:01 > 0:56:02That was amazing!
0:56:11 > 0:56:13Mission accomplished.
0:56:19 > 0:56:23And this intimate footage is now available
0:56:23 > 0:56:25as part of wider scientific studies.
0:56:29 > 0:56:33Supporting evidence that dolphins surf to strengthen friendships,
0:56:33 > 0:56:35develop social skills
0:56:35 > 0:56:39and for the sheer exhilaration of it.
0:56:50 > 0:56:53Next time, the deep.
0:56:54 > 0:56:59A world richer than we ever thought possible,
0:56:59 > 0:57:02where creatures thrive
0:57:02 > 0:57:05in the most extreme conditions on Earth.
0:57:14 > 0:57:18To find out more about our oceans with this free poster, call...
0:57:21 > 0:57:22Or go to...
0:57:26 > 0:57:29..and follow the links to the Open University.