0:00:04 > 0:00:07Only one creature has carved a life for itself
0:00:07 > 0:00:10in every habitat on earth.
0:00:11 > 0:00:14That creature is us.
0:00:17 > 0:00:23All over the world, we still use our ingenuity to survive in the wild places,
0:00:23 > 0:00:28far from the city lights, face to face with raw nature.
0:00:29 > 0:00:33This is the Human Planet.
0:00:44 > 0:00:48The sea covers 70% of our planet's surface.
0:00:50 > 0:00:54It's home to three-quarters of all life on Earth.
0:01:01 > 0:01:04All the creatures found here are perfectly adapted
0:01:04 > 0:01:06to thrive in the ocean...
0:01:09 > 0:01:11..all except one.
0:01:30 > 0:01:32We are not evolved for a life aquatic...
0:01:34 > 0:01:39..and we're way out of our depth in this dangerous and alien world.
0:01:46 > 0:01:51But great opportunities await those people who dare to venture into the water.
0:01:54 > 0:01:58As we immerse ourselves ever deeper in the big blue,
0:01:58 > 0:02:02how do we overcome the enormous challenges that confront us?
0:02:32 > 0:02:36Our relationship with the ocean begins on the coast.
0:02:37 > 0:02:41Even here, the sea is a force to be reckoned with.
0:02:44 > 0:02:47Galicia, in Northern Spain, is home
0:02:47 > 0:02:51to one of Europe's most treacherous coasts.
0:02:53 > 0:02:57But the more extreme the conditions, the greater the rewards,
0:02:57 > 0:03:01if, like Javier and Angel, you're prepared to take the risk.
0:03:01 > 0:03:05THEY SPEAK IN SPANISH
0:03:19 > 0:03:23Javier and Angel are on the hunt for a strange creature
0:03:23 > 0:03:26that clings to the wave-battered rocks...
0:03:26 > 0:03:29at the bottom of these cliffs.
0:03:42 > 0:03:47They have to move fast. Their quarry is only exposed at low tide.
0:03:53 > 0:03:55Vamos! Arriba! Arriba!
0:04:03 > 0:04:05SPEAKS SPANISH
0:04:17 > 0:04:20It's goose barnacles they're after,
0:04:20 > 0:04:24a highly prized delicacy that can sell for 200 euros a kilo.
0:04:25 > 0:04:30But it's not easy pickings. Each year, about five collectors die.
0:04:31 > 0:04:34Few dare work when it's this rough.
0:04:34 > 0:04:38But those who do can charge a premium for their harvest.
0:04:50 > 0:04:54Despite the onslaught, Javier's filled his bag.
0:04:55 > 0:04:59Now it's Angel's turn, and though it's getting even rougher...
0:05:03 > 0:05:05..he's going in with no safety rope.
0:05:12 > 0:05:15Working unattached allows him to dash between waves
0:05:15 > 0:05:19and reach the lowest rocks, where the biggest barnacles grow.
0:05:20 > 0:05:23But one slip could be fatal.
0:05:31 > 0:05:35Although the tide's coming in, Angel's determined to collect more.
0:06:03 > 0:06:06Javier and Angel's gamble paid off.
0:06:06 > 0:06:10In two hours, they've gathered enough goose barnacles
0:06:10 > 0:06:15to fetch around 800 euros. Not bad for a day at the seaside.
0:06:25 > 0:06:31It's this abundance of food that entices us into the waves.
0:06:31 > 0:06:35And just a little further out, there are even greater riches.
0:06:38 > 0:06:41Coastal waters account for just one-tenth of the world's oceans,
0:06:41 > 0:06:45but they're home to the vast majority of marine life.
0:06:50 > 0:06:55The trouble is, as we venture further from the shore, the dangers escalate.
0:07:00 > 0:07:02Benjamin's training to be a harpoonist
0:07:02 > 0:07:07and he knows, any day now, all he's learned could be put to the test.
0:07:25 > 0:07:30He lives on a small Indonesian island called Lembata.
0:07:30 > 0:07:33Few crops grow in this rocky land,
0:07:33 > 0:07:36and even surviving from the sea is a struggle.
0:07:37 > 0:07:39CHATTER
0:07:39 > 0:07:42But there's one animal they wait for
0:07:42 > 0:07:45that can dramatically change their fortunes.
0:07:49 > 0:07:51SHOUTING
0:07:52 > 0:07:53SHOUTING
0:08:02 > 0:08:05The whole village springs into action.
0:08:05 > 0:08:08SHOUTING
0:08:21 > 0:08:24It's a race against time to get out to sea.
0:08:40 > 0:08:42Benjamin and the rest of the crew
0:08:42 > 0:08:46are about to take on the biggest predator that's ever lived.
0:08:58 > 0:08:59They all know the risks,
0:08:59 > 0:09:03but opportunities don't come much bigger than this.
0:09:05 > 0:09:07The sperm whale.
0:09:07 > 0:09:09WHALE SONG
0:09:09 > 0:09:15Up to 18 metres long, these mighty leviathans are powerful animals
0:09:15 > 0:09:17and they won't go down without a fight.
0:09:26 > 0:09:29With simple wooden boats and handmade weapons,
0:09:29 > 0:09:35the whalers seem ill-prepared for battle, but this is how it's been for 600 years.
0:09:36 > 0:09:41They can only harpoon the whale when it surfaces to breathe...
0:09:43 > 0:09:44..so they need to move fast.
0:09:53 > 0:09:57Benjamin's brother prepares to launch himself at the whale.
0:09:58 > 0:10:01This is the most dangerous moment of all.
0:10:07 > 0:10:09But he misses...
0:10:13 > 0:10:16..and now someone else must step up before the whale dives.
0:10:16 > 0:10:19SHOUTING
0:10:19 > 0:10:21Benjamin's moment has arrived.
0:10:42 > 0:10:44He's got it.
0:10:48 > 0:10:51But the battle has just begun.
0:10:55 > 0:11:00As the whale fights to break free, they move to harpoon it again.
0:11:06 > 0:11:09They need to prevent it from diving and pulling a boat under.
0:11:17 > 0:11:20But it's not enough.
0:11:23 > 0:11:28Terrified of the thrashing whale, the crew scramble to safety.
0:11:39 > 0:11:43Another boat attacks and harpoons the whale once more.
0:11:52 > 0:11:57Now dragging several boats, the whale slowly tires.
0:12:10 > 0:12:13Eventually, its struggles are exhausted
0:12:13 > 0:12:17and a final cut, through its backbone, is made.
0:12:33 > 0:12:37It's been an epic eight-hour battle,
0:12:37 > 0:12:41but Benjamin has shown his skill and bravery...
0:12:46 > 0:12:50..and this time everyone returns safely home.
0:12:52 > 0:12:58The death of a whale may be sad to us, but this is their lifeline.
0:12:58 > 0:13:01One catch can feed a village for months,
0:13:01 > 0:13:08and this small-scale hunt in Lembata doesn't threaten whale numbers in these oceans.
0:13:08 > 0:13:12They only take around six whales a year.
0:13:13 > 0:13:18Nothing is wasted. The meat is shared out.
0:13:18 > 0:13:23As the man who dealt the decisive blow, Benjamin gets a larger share.
0:13:24 > 0:13:29And for a while at least, his family won't be going hungry.
0:13:35 > 0:13:38Although we've evolved for a life on land,
0:13:38 > 0:13:41we've become remarkably efficient oceanic hunters.
0:13:46 > 0:13:48Adaptability is the secret of our success
0:13:48 > 0:13:52at discovering new ways to exploit the ocean.
0:13:57 > 0:14:03And in a few special places, this means working with the creatures of the sea.
0:14:10 > 0:14:13These fishermen of Laguna in Brazil
0:14:13 > 0:14:16have forged one of the most extraordinary partnerships
0:14:16 > 0:14:20between humans and wild animals found anywhere on Earth.
0:14:25 > 0:14:29Edson is up early to fish the large numbers of mullet
0:14:29 > 0:14:33that migrate through these waters every May.
0:14:34 > 0:14:36But there's a problem.
0:14:36 > 0:14:42The water's so murky the fishermen can't see where to cast their nets.
0:14:44 > 0:14:50So they join forces with the most intelligent animal in the sea.
0:14:50 > 0:14:55But, like all relationships, a certain amount of patience is required.
0:15:04 > 0:15:07Finally, their friends surface.
0:15:07 > 0:15:10CLICKING AND WHISTLING
0:15:10 > 0:15:15The local bottlenose dolphins are celebrities in Laguna.
0:15:15 > 0:15:21In fact, Edson and his pal Alfredo know each one by name.
0:15:28 > 0:15:34Incredibly, the dolphins drive the mullet towards the fishermen,
0:15:34 > 0:15:40and even signal when to cast their nets, with these distinctive dives.
0:15:57 > 0:16:00The fishermen say they can tell the size of the school,
0:16:00 > 0:16:02and which way it's travelling
0:16:02 > 0:16:05from the vigour and direction of the dive.
0:16:12 > 0:16:15The dolphins do the hard work herding the mullet.
0:16:17 > 0:16:20The fish are served to the fishermen on a plate...
0:16:24 > 0:16:28..but what the dolphins stand to gain is less clear.
0:16:28 > 0:16:30Since they detect prey by echolocation,
0:16:30 > 0:16:33they have no problem hunting in the murky water,
0:16:33 > 0:16:37but picking off individuals from the school is more difficult.
0:16:38 > 0:16:42It seems the nets panic the fish into breaking formation,
0:16:42 > 0:16:46making them much easier for the dolphins to chase down.
0:16:59 > 0:17:06As the nets are hauled in, the benefits of teamwork are revealed.
0:17:12 > 0:17:15Edson and the other fishermen have no doubt
0:17:15 > 0:17:17how much the dolphins help them.
0:17:53 > 0:17:59No matter how we catch it, seafood is vital to human survival,
0:17:59 > 0:18:05providing the main source of protein for about half the world's population.
0:18:10 > 0:18:15But there's a lot more to our ancient connection with the sea than just food.
0:18:17 > 0:18:20The more we've come to depend on the ocean,
0:18:20 > 0:18:23and the further we've pushed into its vast frontier,
0:18:23 > 0:18:27the greater its influence has become in our lives.
0:18:32 > 0:18:35The Pacific covers one-third of the globe.
0:18:39 > 0:18:42The tiny specks of land in the middle of it
0:18:42 > 0:18:45are about as remote as life can get for a human being.
0:18:58 > 0:19:00With so few options on land,
0:19:00 > 0:19:06the surrounding ocean underpins almost every aspect of life on a Pacific island.
0:19:17 > 0:19:21Over 3,000 kilometres from the nearest continent,
0:19:21 > 0:19:25Hawaii is one of the most isolated of all.
0:19:27 > 0:19:33There are few places where the sea has had a greater impact on human existence.
0:19:33 > 0:19:36CHANTING SONG
0:19:49 > 0:19:53- MAN:- The ocean, significantly to us, it's our home.
0:19:53 > 0:19:59Our connection is so great, we look at it as our origin.
0:19:59 > 0:20:03The water is who we are, and the water is our mother, our father, our gods.
0:20:06 > 0:20:10For Tom "Pohako" Stone, displaying his skill in the ocean
0:20:10 > 0:20:14is a central part of what it means to be Hawaiian.
0:20:21 > 0:20:23Sliding on waves, as it was known,
0:20:23 > 0:20:26has been practised by the Polynesians for millennia.
0:20:26 > 0:20:31But it was around 1,000 years ago, when they arrived in Hawaii,
0:20:31 > 0:20:33that it evolved into surfing.
0:20:33 > 0:20:38- TOM:- When we actually learned that we could construct boards
0:20:38 > 0:20:41to stand up and surf a wave,
0:20:41 > 0:20:46it became a very ritualistic component of our culture.
0:20:48 > 0:20:55Far more than just a sport, surfing was a sacred art form for Tom's ancestors.
0:20:55 > 0:20:57It was a core part of their society,
0:20:57 > 0:21:03and the noble pursuit of warriors, kings and queens.
0:21:08 > 0:21:12- TOM:- We have a lot of history about women that...that surf,
0:21:12 > 0:21:17and, you know, they surfed so well that they actually reached godly status.
0:21:22 > 0:21:25We revered these women.
0:21:36 > 0:21:39From ancient origins, surfing has now gone global.
0:21:40 > 0:21:44And for some, searching for the ride of your life
0:21:44 > 0:21:46has become an extreme obsession.
0:21:54 > 0:21:57December 9th, 2009.
0:21:57 > 0:22:00The world's surfing elite has gathered in Hawaii
0:22:00 > 0:22:05to ride some of the biggest swells to hit these shores in over a decade.
0:22:24 > 0:22:29Surfing's certainly changed, but for many it's still a way of life
0:22:29 > 0:22:32and the best riders are still revered as gods
0:22:32 > 0:22:35amongst the worldwide surfing tribe.
0:22:46 > 0:22:50With waves over 15 metres, five storeys high,
0:22:50 > 0:22:54this is a real test of skill and stamina.
0:23:19 > 0:23:23Ken Bradshaw is famed for taming a 26-metre wave,
0:23:23 > 0:23:26probably the biggest ever ridden.
0:23:26 > 0:23:31But these unpredictable swells can claim even the most seasoned surfer.
0:23:53 > 0:23:56Trapped in a rolling mountain of white water,
0:23:56 > 0:24:00Ken is tossed around like a rag doll in a washing machine.
0:24:03 > 0:24:07Just as he surfaces, another giant breaker comes crashing in.
0:24:26 > 0:24:29After a relentless pounding from six successive waves,
0:24:29 > 0:24:33Ken eventually escapes in one piece.
0:24:38 > 0:24:41All big wave surfers know the risks,
0:24:41 > 0:24:45but the adrenaline and the glory is addictive.
0:24:47 > 0:24:50And just as the ancient Hawaiians discovered,
0:24:50 > 0:24:53surfing is still the most spectacular demonstration
0:24:53 > 0:24:56of our ability to conquer the waves.
0:25:55 > 0:26:01Our mastery of the sea is impressive, but we'll never tame its full fury.
0:26:03 > 0:26:06The enormous waves of December 9th
0:26:06 > 0:26:11were created by intense tropical cyclone activity in the Pacific.
0:26:13 > 0:26:18When warm waters fuel the ferocity of depressions over the ocean,
0:26:18 > 0:26:21they can create the most violent weather systems on Earth.
0:26:23 > 0:26:26People must stay well away from the raging sea
0:26:26 > 0:26:29during these tempestuous times,
0:26:29 > 0:26:31but they can't stop it coming to them.
0:26:38 > 0:26:43These super-storms, with winds of over 300 kilometres per hour,
0:26:43 > 0:26:45wreak havoc on the human world.
0:26:47 > 0:26:50SHOUTING
0:26:50 > 0:26:53It can take years to recover from the destruction.
0:26:56 > 0:26:58SHOUTING
0:27:01 > 0:27:05Sometimes over 1,600 kilometres wide,
0:27:05 > 0:27:11hurricanes and typhoons are persistent reminders of the ocean's awesome force.
0:27:15 > 0:27:19It's little wonder that coastal people look at these mighty waters
0:27:19 > 0:27:20with great reverence...
0:27:22 > 0:27:25..but not just for the power of the ocean,
0:27:25 > 0:27:28but also the power of the creatures that live in it.
0:27:33 > 0:27:40In the islands off Papua New Guinea, Blais is known as a sorcerer of the sea.
0:27:45 > 0:27:50Possessing the mysterious ability to summon sharks from the deep,
0:27:50 > 0:27:54he's one of the last so-called shark callers,
0:27:54 > 0:27:58a traditional hunting technique steeped in superstition.
0:28:17 > 0:28:19HE CHANTS SONG
0:28:32 > 0:28:36Blais respects ritual, but he also understands shark behaviour.
0:28:36 > 0:28:43Rattling in the water mimics the activity of feeding fish.
0:28:43 > 0:28:46Sharks can detect these vibrations from three kilometres away,
0:28:46 > 0:28:49but they don't always respond.
0:28:49 > 0:28:51HE CHANTS SONG
0:28:54 > 0:28:57RATTLING
0:29:13 > 0:29:15RATTLING
0:29:15 > 0:29:19And as industrial fishing decimates shark numbers,
0:29:19 > 0:29:22the waits are getting even longer.
0:29:27 > 0:29:29RATTLING
0:29:33 > 0:29:38Finally, a grey reef shark emerges from the blue.
0:29:39 > 0:29:42Blais has appeased its spirit.
0:29:43 > 0:29:49But now he has to catch it, and sharks are notoriously skittish.
0:29:55 > 0:29:57It's a game of cat and mouse.
0:30:04 > 0:30:09Blais tries to entice the shark close enough to slip a noose around its neck...
0:30:13 > 0:30:17...but one false move and it's game over.
0:30:21 > 0:30:27Finally it takes the bait. Slowly he prepares the noose.
0:30:50 > 0:30:54Blais can't keep hold of the thrashing shark,
0:30:54 > 0:30:58but this wooden float prevents it diving.
0:31:16 > 0:31:21Then, as if under a spell, the shark suddenly stops.
0:31:28 > 0:31:32But in fact the float exploits a quirk in shark biology,
0:31:32 > 0:31:38exhausting it so much, it enters a state known as tonic immobility.
0:31:41 > 0:31:43Blais approaches with caution.
0:31:44 > 0:31:49The shark is still very much alive and its bite could cause serious injury.
0:32:02 > 0:32:06In the past, Blais would have killed the shark for food.
0:32:08 > 0:32:11But today he lets it go free.
0:32:14 > 0:32:18Blais is committed to keeping his shark-calling culture alive...
0:32:18 > 0:32:20SOUNDING CONCH
0:32:23 > 0:32:26...and this means keeping sharks alive.
0:32:43 > 0:32:47And it's not just traditions that are threatened.
0:32:48 > 0:32:50In some seas around the world,
0:32:50 > 0:32:54a growing shortage of fish is forcing people deeper and deeper,
0:32:54 > 0:32:57just to land a decent catch.
0:32:58 > 0:33:03So deep, they venture to the very limits of human survival.
0:33:08 > 0:33:11Welcome to the world of the Pa-aling divers,
0:33:11 > 0:33:15perhaps the most dangerous fishing method of all.
0:33:16 > 0:33:2080 men, many of whom are still teenagers,
0:33:20 > 0:33:23are preparing to dive to over 40 metres,
0:33:23 > 0:33:29breathing air pumped through these makeshift tubes by this rusty compressor.
0:33:30 > 0:33:36Joseph is one of the youngest aboard, but he's aware of the risks.
0:33:43 > 0:33:47He's already witnessed just how lethal his job can be.
0:34:05 > 0:34:08The seas around the Philippines were once rich with life,
0:34:08 > 0:34:10but they've been so over-exploited
0:34:10 > 0:34:16that decent fish numbers are only found at perilous depths.
0:34:19 > 0:34:21SHOUTING
0:34:30 > 0:34:35The divers guide the huge ball of nets 40 metres down to the sea floor,
0:34:35 > 0:34:38but all the while their air supply is at risk.
0:34:40 > 0:34:42Back on the boat,
0:34:42 > 0:34:45the ailing compressor and the ever-worsening tangle of tubes
0:34:45 > 0:34:47need constant attention.
0:34:49 > 0:34:54Like a failing heart pumping through clogged arteries,
0:34:54 > 0:34:56if this circulation system fails,
0:34:56 > 0:35:00at this depth, it's almost certain death.
0:35:07 > 0:35:09Joseph and the team unravel the nets
0:35:09 > 0:35:12and lay them out by securing them to rocks.
0:35:25 > 0:35:26They must work fast.
0:35:26 > 0:35:30Joseph knows, the longer he spends at these depths,
0:35:30 > 0:35:32the more dangerous it becomes.
0:35:32 > 0:35:36With every breath, more nitrogen dissolves in his body,
0:35:36 > 0:35:41making him increasingly vulnerable to decompression sickness - "the bends".
0:36:01 > 0:36:05The top of the net is suspended by plastic containers filled with air,
0:36:05 > 0:36:09creating a huge cavernous trap beneath.
0:36:17 > 0:36:20Now it's time to set the scare line.
0:36:30 > 0:36:36The boats drag the 1,000-metre line to form a huge circle around the net,
0:36:36 > 0:36:39and the divers position themselves along it.
0:36:42 > 0:36:48Joseph and the team begin closing the trap by swimming towards the net.
0:36:48 > 0:36:51The waving streamers and the curtain of rising bubbles
0:36:51 > 0:36:54panics the fish and they flee.
0:37:01 > 0:37:04As the line of divers tightens, more and more fish
0:37:04 > 0:37:07swim straight into the gaping net.
0:37:13 > 0:37:15This deep-sea round-up is so effective,
0:37:15 > 0:37:19it can take 50% of the fish from a reef.
0:37:35 > 0:37:39The net is closed, and now Joseph must do something even more dangerous,
0:37:39 > 0:37:43get inside and herd the catch to the far end.
0:38:02 > 0:38:07On deck, the tangled web of tubes is getting worse.
0:38:25 > 0:38:29Once the catch is concentrated, the net is released from its anchor points.
0:38:36 > 0:38:39Now comes the most lethal stage of all -
0:38:39 > 0:38:42guiding the net as it shoots to the surface.
0:38:42 > 0:38:47All too often, the divers ascend too quickly and get the bends.
0:39:07 > 0:39:11As the catch is hauled onto the boat, its size is revealed.
0:39:13 > 0:39:16Just under a tonne of fish isn't bad
0:39:16 > 0:39:21but it's nowhere near what these fishermen were landing a few years ago.
0:39:22 > 0:39:24And this isn't the only problem.
0:39:24 > 0:39:27Some of the crew do have the bends.
0:39:28 > 0:39:32One diver has returned to the bottom to relieve the symptoms,
0:39:32 > 0:39:36whilst, closer to the surface, another is massaged
0:39:36 > 0:39:39to release the painful bubbles in his spine.
0:39:44 > 0:39:46Every day, these Pa-aling divers
0:39:46 > 0:39:50are taking greater risks for dwindling rewards.
0:40:10 > 0:40:12Joseph has his dreams,
0:40:12 > 0:40:19but the harsh reality is he'll be diving twice again today just to make ends meet.
0:40:22 > 0:40:24We've become so successful in the ocean
0:40:24 > 0:40:30it's predicted that in 50 years almost all the fish could be gone...
0:40:32 > 0:40:35..and this may not be the only change to come.
0:40:37 > 0:40:41All around the world, sea levels are rising.
0:40:41 > 0:40:45Soon our planet could be even more dominated by the ocean,
0:40:45 > 0:40:50and our ability to survive here will be pushed to the very limit.
0:40:57 > 0:41:02Yet there are some people who've already adapted to life in a water world.
0:41:07 > 0:41:12In the coral seas between Borneo, Sulawesi and the Philippines,
0:41:12 > 0:41:16there are people who live more intimately with the ocean
0:41:16 > 0:41:18than any other culture on earth.
0:41:27 > 0:41:32The Bajau Laut build their lives in the middle of the sea,
0:41:32 > 0:41:34often many kilometres from land.
0:41:34 > 0:41:37CHATTERING
0:41:46 > 0:41:51The ocean has a profound influence on every aspect of their existence.
0:41:51 > 0:41:54They even measure the passage of time by the rhythm of the tides
0:41:54 > 0:41:57rather than minutes and hours.
0:42:05 > 0:42:10And there are some whose relationship with the sea runs even deeper.
0:42:19 > 0:42:22The Bajau, who live on houseboats,
0:42:22 > 0:42:26have almost completely severed their ties with the land.
0:42:31 > 0:42:34Nohara rarely sets foot ashore.
0:43:00 > 0:43:07Nohara and her family usually only visit land to trade for rice and fuel,
0:43:07 > 0:43:10or to mend their boats.
0:43:10 > 0:43:13But, like many Bajau, Nohara gets "land-sick"
0:43:13 > 0:43:16and she prefers to stay aboard.
0:43:18 > 0:43:23Her family has no nationality, no fixed abode and almost no money,
0:43:23 > 0:43:26but the ocean provides everything they need.
0:43:29 > 0:43:33They eat a bewildering variety of seafood.
0:43:40 > 0:43:45Her children adapt to an aquatic way of life from a very young age.
0:43:49 > 0:43:53Some Bajau children spend so much time in the sea,
0:43:53 > 0:43:56their eyes adjust to focus better underwater.
0:44:00 > 0:44:05But there's one member of this community whose adaptation is even more staggering.
0:44:08 > 0:44:11Sulbin is an underwater hunter,
0:44:11 > 0:44:15and the living proof of just how far we can push our bodies
0:44:15 > 0:44:17towards a life aquatic.
0:44:40 > 0:44:46Sulbin's search for supper takes him on an incredible journey under the waves,
0:44:46 > 0:44:50and his abilities will take your breath away.
0:44:54 > 0:44:59First he prepares by entering a trance-like state.
0:45:18 > 0:45:25Sulbin is about to push his body almost beyond the realms of possibility,
0:45:25 > 0:45:28and if you want to try and join him, get ready to hold your breath
0:45:28 > 0:45:30for as long as you can.
0:45:36 > 0:45:39He takes one last breath.
0:46:01 > 0:46:07Focused and calm, Sulbin descends 20 metres to the sea floor.
0:46:17 > 0:46:21His heartbeat slows to around 30 beats per minute.
0:46:22 > 0:46:25The pressure at these depths crushes his chest,
0:46:25 > 0:46:30squeezing the air in his lungs to one-third of its usual volume,
0:46:34 > 0:46:37Even without weights, he's negatively buoyant enough
0:46:37 > 0:46:42to stride across the bottom of the sea as if hunting on land.
0:46:59 > 0:47:03By now, the carbon dioxide in his blood causes
0:47:03 > 0:47:06an almost irresistible urge to gasp for air,
0:47:06 > 0:47:10but Sulbin must keep his mind on the hunt.
0:47:19 > 0:47:25After a minute and three-quarters, Sulbin spots a fish.
0:47:36 > 0:47:43Sulbin can go even deeper than this and stay down for up to five minutes,
0:47:44 > 0:47:48but he's not one to show off and, after all, he's got what he came for.
0:47:51 > 0:47:57Two-and-a-half minutes of hunting under pressure on one breath.
0:47:57 > 0:48:01Perhaps the idea of humans existing as marine mammals
0:48:01 > 0:48:03is not so far-fetched after all.
0:48:15 > 0:48:18Through amazing adaptability and endeavour,
0:48:18 > 0:48:22we've pushed our limits of survival into the ocean
0:48:22 > 0:48:25and, as we've immersed ourselves deeper in the sea,
0:48:25 > 0:48:29it's had a profound effect on our lives.
0:48:35 > 0:48:40But as we continue to change the nature of the greatest environment on our planet,
0:48:40 > 0:48:45how we'll adapt in the future remains to be seen.
0:48:57 > 0:49:01The most technical and demanding shoots for the Human Planet: Oceans programme
0:49:01 > 0:49:04were those that took place underwater.
0:49:06 > 0:49:10The dive camera crew were well prepared to film fishermen in the Philippines.
0:49:10 > 0:49:15But they weren't quite prepared for the dangers they witnessed
0:49:15 > 0:49:17and the friendships they'd forge.
0:49:21 > 0:49:23Liminangcong is home to the 80
0:49:23 > 0:49:26Pa-aling fishermen that the film crew will follow.
0:49:42 > 0:49:47Two fishing boats are crammed with 80 divers, their food and provisions,
0:49:47 > 0:49:50before heading out for two weeks at sea.
0:49:54 > 0:49:56At the fishing grounds, Simon and Roger are playing catch-up,
0:49:56 > 0:50:01as their technical underwater equipment is slowing them down.
0:50:01 > 0:50:03They've dropped the lines. They didn't even tell us.
0:50:03 > 0:50:06The captain seems to be on a mission to prove something today
0:50:06 > 0:50:08so we've got to go fast.
0:50:11 > 0:50:15Underwater filming is risky, but these risks are nothing
0:50:15 > 0:50:19compared to those faced daily by the compressor divers.
0:50:23 > 0:50:27Compressor diving is a dangerous way to make a living.
0:50:28 > 0:50:31Air, often tainted with diesel,
0:50:31 > 0:50:34is pumped through thin plastic tubes right down to the divers.
0:50:37 > 0:50:41At 64, Joning is one of the veterans on the boat,
0:50:41 > 0:50:44and knows the harsh realities of compressor diving.
0:50:58 > 0:51:02Most of the divers are young and fit, and they need to be.
0:51:02 > 0:51:03It's physically demanding work,
0:51:03 > 0:51:08and the men are totally reliant on the compressor to keep them breathing.
0:51:24 > 0:51:29To use, basically, what's essentially a garden hose down at 25 metres,
0:51:29 > 0:51:30to pump air into your mouth, is just mad.
0:51:33 > 0:51:37The biggest danger for these fishermen is known as
0:51:37 > 0:51:40decompression sickness, or "the bends".
0:51:42 > 0:51:46The bends can happen when divers have been down deep for a long time,
0:51:46 > 0:51:49and then come up too quickly to the surface.
0:51:49 > 0:51:52Nitrogen is absorbed into the body
0:51:52 > 0:51:53and, as the divers rise up,
0:51:53 > 0:51:58bubbles are formed that can lodge in the joints, causing intense pain.
0:52:01 > 0:52:06Two guys are in real trouble on this deep dive.
0:52:06 > 0:52:09Martin, a young diver, is in such pain
0:52:09 > 0:52:13that his friend tries to relieve it by massaging him.
0:52:15 > 0:52:18Once on the surface, it's obvious to everyone
0:52:18 > 0:52:20that Martin is still in trouble.
0:52:23 > 0:52:30If not treated, the bends can lead to permanent injuries and even death.
0:52:32 > 0:52:37Meanwhile, the second diver, Michael, is also having problems.
0:52:37 > 0:52:40It seems like two men just came up with the bends.
0:52:40 > 0:52:42They went pretty deep on this dive, trying to get more fish.
0:52:42 > 0:52:46But we've taken them onto our boat to get some medical attention
0:52:46 > 0:52:49so, hopefully, they're all right.
0:52:50 > 0:52:54Simon tries to relieve their symptoms with the crew's first aid supplies.
0:52:54 > 0:52:56One more.
0:52:56 > 0:52:59Michael's had 15 minutes on oxygen. Now put Martin
0:52:59 > 0:53:03onto another set of 15 minutes. This is the...you know,
0:53:03 > 0:53:05the rudimentary decompression first aid
0:53:05 > 0:53:07we can give them at the moment -
0:53:07 > 0:53:11give them oxygen, give them water to rehydrate and keep them warm.
0:53:11 > 0:53:15Both of them are saying that their symptoms are decreasing
0:53:15 > 0:53:19and they are looking a lot more happy than they did about half an hour ago.
0:53:19 > 0:53:21He gives them oxygen,
0:53:21 > 0:53:25which helps reduce the nitrogen in their bodies and relieves their pain,
0:53:25 > 0:53:28but even this most basic of diving first aid
0:53:28 > 0:53:31is not normally available to the Pa-aling fishermen.
0:53:31 > 0:53:33No pain?
0:53:33 > 0:53:35This isn't surprising
0:53:35 > 0:53:39as the fishermen in the Philippines belong to the lowest wage earners in the country,
0:53:39 > 0:53:44earning about 25 US dollars for a week's work.
0:53:45 > 0:53:48However, for many, like Joning and his family,
0:53:48 > 0:53:51this is their whole way of life.
0:54:22 > 0:54:26His son had got the bends, and now has to use crutches.
0:54:27 > 0:54:32But this isn't the only time the dangers of compressor diving
0:54:32 > 0:54:33have hit Joning's family.
0:55:06 > 0:55:08I'm very sorry about that.
0:55:08 > 0:55:12- WOMAN TRANSLATES FROM ENGLISH - Yeah. That's terrible.
0:55:12 > 0:55:14- MUTTERS - That's really...
0:55:14 > 0:55:17- That's really sad, isn't it?- It is.
0:55:28 > 0:55:31Having spent a week living and working with the compressor divers,
0:55:31 > 0:55:35Simon and Roger have become very close to the fishermen.
0:55:35 > 0:55:37CHATTERING
0:55:37 > 0:55:40To fully understand their way of life,
0:55:40 > 0:55:45Simon needed to experience first-hand what it's like to be a compressor diver.
0:55:47 > 0:55:52So Joning is keen to take him on a shallow dive.
0:55:52 > 0:55:53AIR HISSES
0:55:53 > 0:55:57I've seen the boys do it. They've made it look easy.
0:55:57 > 0:56:00But we've had several guys that have gone down with symptoms of the bends.
0:56:00 > 0:56:04I've got to admit that I'm feeling a little bit apprehensive.
0:56:09 > 0:56:14Simon has scuba-dived for 16 years and has logged over 3,000 dives,
0:56:14 > 0:56:18but this is diving at its most basic.
0:56:24 > 0:56:28About the first minute, I got sent out,
0:56:28 > 0:56:31I was, er...a little bit petrified, actually.
0:56:31 > 0:56:36This is a violent thing. It's just punching air down your throat.
0:56:36 > 0:56:37It's quite mad.
0:56:37 > 0:56:40It took me a minute to kind of get myself under control
0:56:40 > 0:56:42and then once you've got the hang of it,
0:56:42 > 0:56:45and once you believe in it and trust in it, then you can swim on.
0:57:03 > 0:57:06There were a couple of times when I lost it, though.
0:57:06 > 0:57:08I was flailing around everywhere.
0:57:08 > 0:57:11I was trying to find it again and get it back in.
0:57:11 > 0:57:17But Joning was keeping a good eye on me, and the rest of the guys were as well,
0:57:17 > 0:57:22but I wouldn't want to do that for a whole fish-catching session
0:57:22 > 0:57:24that's for sure.
0:57:25 > 0:57:29A strong camaraderie between the divers has been forged.
0:57:29 > 0:57:33The film crew have captured a dramatic sequence,
0:57:33 > 0:57:37and the fishermen head home happy, with a boatload of fish to sell.
0:57:56 > 0:58:02Joning and everyone on board have finished another Pa-aling fishing trip,
0:58:02 > 0:58:05and all can return safe and sound to their families.