"The Northern Isles, where the Atlantic meets the North Sea." "Giant rock stacks, treacherous seas, secret bays and over 170 islands" "This is the northernmost extreme of the British Isles." "Over there, it's the Arctic Circle." "In that direction, it's Norway." "This is the very edge." "Our new adventures start at the tip of Shetland down to the tail of Orkney." "Along the way, I'm joined by some familiar faces." "Alice Roberts examines an ancient Shetlander." "That's someone who lived 1,800 years ago." "Nick Crane hunts for evidence of a giant killer wave!" "A wall of water 20 metres high." "Miranda Krestovnikoff is on the trail of Orkney's elusive underwater thief - the octopus." "And Mark Horton searches for hidden dangers that wreck unwary ships." "12, 11..." "We should be keeping our fingers crossed. ..10." "This is terrifying." "Me?" "My destination is one of the most amazing sights in the British Isles and a great adventure." "Welcome to the story of Coast in the Northern Isles." "You could be forgiven for thinking Shetland and Orkney are located in boxes off Scotland - it's usually how they appear on maps." "In fact, we're headed 250 miles north of Aberdeen." "From Shetland, we're hopping over to Fair Isle, before we reach Orkney and our final destination - the Old Man of Hoy." "Our journey begins at the very top" " Muckle Flugga." "This lighthouse is the first sighting of British soil for northern seafarers." "What a fantastic place to start our journey on Unst, the most northerly inhabited island in the British Isles." "I already know a few things about Shetland - it hasn't got any trees, it's had an oil boom and its history is more Scandinavian than Scottish." "But when you get here you find this - an early warning station." "Saxa Vord used to track German U-boats and Soviet aircraft." "But it's not on red alert any more." "Now the island's going green." "This tiny car runs on hydrogen gas!" "'It's the brainchild of Unst man Ross Gazey.' Ross." " Hi, Neil." " How you doing?" " Not too bad." "What is a hydrogen-powered car doing on Unst?" "Well, I had this idea for hydrogen power and all the things it could be used for and this car has become part of that." "Where do you get hydrogen from?" "You don't see a lot of that in the cold counter at the supermarket!" "We actually make our own hydrogen from wind power and tap water." " You're pulling my leg." " Not at all." "We take electrical power from the wind turbines that we have and we use it to generate hydrogen from tap water and you do that just by passing your electrical current through water and it breaks water down into hydrogen and oxygen." " Couldn't give us a lift, could you?" " No problem." "Jump in." " Excellent." "'This car's got no harmful emissions." "'The only thing that comes out of the exhaust is water.'" "What is the top speed of the vehicle?" "45 miles an hour." "Hi-tech hydrogen cars might be the island's future, but right now this one's taking me on a journey back in time." "I'm travelling down the east coast of Shetland to Baltasound." "This is exactly the sort of scene I was expecting - just a few houses and buildings dotted about." "There's not a soul to be seen." "It's very peaceful and quiet." "But I know for a fact that here at Baltasound, it wasn't always this way." "This was once a boom town." "In its heyday the prize was silver, the "silver darlings of the sea"" " herring." "'Ian Napier knows the story.'" "What would this bay have looked like at the height of the herring boom?" "It would have been a real hive of industry." "There's a record of as many as 16,000 people here for the herring season." "So this place would just have been, well, crowded." "Yeah." "I mean, you hear stories about being able to cross the bay without getting your feet wet." "There were more than 2,000 fishing boats based in Shetland for the season." "There would have been a series of piers and each one would have had a little huddle of buildings with it." "When the fleet was in, it must have been very crowded." "At its peak in 1905, almost a quarter of a million barrels of cured herring were packed here and dispatched to Eastern Europe." "It created opportunities." "The gutting and the packing of the herring into the barrels was all done by women." "There would have been thousands of women working here." "It was perhaps the first time that they had had the opportunity to earn cash." "The boom was inevitably followed by bust." "By the 1930s, bigger, faster ships started to bypass Baltasound and this small harbour fell silent." "Shetlanders have to live with the ebb and flow of opportunities." "The history of their struggle is written around the ribbon of this coast." "Remarkable secrets of an ancient civilization are beginning to emerge at Sandwick Bay." "When coastal erosion revealed curious stones, the foundations of a 2,000-year-old settlement, the islanders got together with a team of archaeologists to unearth their Iron Age past." "It's the discovery of a virtually intact skeleton that makes this dig so exciting." "Who is this?" "And what can their burial tell us about this ancient society?" "It's a mystery that bone expert Dr Alice Roberts hopes to solve." "Now this dig is quite special to me because it's a chance to find out more about prehistoric Shetland and to find out specifically about the lives of people in the Iron age here on Unst, but also to meet one of those people." "The islanders are working with Dr Olivia Lelong and her team to investigate this community and their unusual buildings." "It is literally right on the shore, isn't it?" "Yeah, you can see the wall standing up here, and it would have carried on up, probably curving around like that with the slabs forming walls and the roof." "And all of this construction is going on in stone, which is very weird compared with the rest of Britain where you've got a lot of timber round houses being built in the Iron Age." "Here you've got buildings with stone floors, stone walls, stone roofs." "Yes, just using what they had in clever ways." "They didn't have trees so they used the materials they had to hand." "The discovery of hearths, fish and animal bones and pottery suggests that these are homes." "But who was living here?" "I've been asked to put my skills as a bone expert to the test and examine the remains of this ancient islander." "The bones have been carbon dated at 1,800 years old, but that's all that's known." "It is quite unusual to have bones this well preserved, so this means the better preserved they are, the more they can tell us." "We'll be able to tell whether this person's male or female, how tall they were, how healthy they were in childhood, and that's somebody who lived 1,800 years ago on Unst." "The volunteers have christened the skeleton their "Pictish Princess"." "The Picts lived in northern Scotland around 1,800 years ago, a date that matches these bones." "So Pictish maybe, but a princess?" "What does the skeleton tell us?" "Is it a she or a he?" "If you just take one of these pelvic bones and just look at it." "And the narrowness of that would very much lead me to the conclusion that this is likely to be male." "In terms of what you can look for on the skull, there is a ridge above the ear hole just here." "So that's masculine." "And quite a nose!" "I'm going to say on balance I think it's a male and it's a male with quite a nose on him." "Now I know the sex," "I can calculate his height from his bone measurements." "Five foot seven, so he's the same height as me." "There's no evidence of disease or malnutrition here." "This coastline provided a rich, varied diet for these Iron Age people." "The teeth are in pretty good condition, actually." "There's no tooth decay." "So this is a young adult, who if they were alive today, wouldn't need to have any fillings." "'We're gradually piecing together what life was like 'for this ancient community but there's more.'" " Are these some of the artefacts that were buried with it?" " Yes." "That's amazing that it was actually found in the excavation." "It's so tiny." "It's a spiral of copper alloy bronze with two little rings of what might be glass." " That's amazing." " This was placed just beside the mouth." "There's various theories about what they were." "I think the most popular is that they were mirrors or a picture of the moon." "It almost looks like it's got craters on it, doesn't it?" " It's one of these things we'll never know." " Probably not." "'But there is one thing I can say for certain.'" "It's not a Pictish princess, it's a male skeleton." "Really?" "A boy." "A Pictish prince." " A Pictish prince, yeah." " There you go." "This coast once nurtured a people who didn't just survive here, they had an appreciation of beauty, they made exquisite things and they shared a culture where respect for the dead was important." "1,800 years ago, a young man was buried on this beach looking out to sea, and this burial and in fact the whole excavation has brought together the community to uncover its own heritage and to find out what it really means to be an islander on Unst." "Over 100 islands make up Shetland, creating a coastline that's a staggering 900 miles long." "On mainland Britain, you're never more than 72 miles from the sea." "Here on Shetland, that maximum distance is three miles." "Life here is about as coastal as it gets." "Living so close to the sea certainly isn't stress free." "These islands are in the firing line for some of the most severe storms in the British Isles." "Force ten gales and 30-foot waves are common." "The north-west mainland is the worst hit - it bears the brunt of the North Atlantic storm track." "That's where Nick Crane is headed." "I'm on the coast of Esha Ness, one of the most remote spots in the British Isles." "On one side, hundreds of acres of bog and moor, on the other side, the North Atlantic." "Between the sea and the land, a narrow coastal battleground." "On the defence, the ancient rocks of Shetland." "On the attack, the power of waves." "This is the Grind O' Da Navir." "The rock was created millennia ago by volcanic lava flow." "Now all that remains of the cliff top is a spectacular amphitheatre hewn out of the rock by gigantic storm waves." "I want to know how the titanic battle between sea and rock reshapes this coast." "Someone who's as captivated by the sea's power as I am is local geologist Allen Fraser." "I was out here on 12th January last year when we had a really big storm, one that quarried out these boulders." "In 2005, Allen recorded this video." "It captures the aftermath of a 70mph gale that tore into the rock, leaving its mark on the cliff top." "This is a massive boulder field, isn't it?" "There's a very large boulder beach here." "I first thought this was a quarry and I wondered why on Earth would anyone want to build a quarry here." "In a way, I was right because it is a quarry but not a manmade quarry." "I've never seen anything like it anywhere." "I'll show you some fresh quarrying marks." "A large block has been prised off the cliff." " You can see how fresh it is." " That's impressive." "So these rocks getting pulled out of the bedrock and then just flung back and back and back" " until they hit the big ridge at the back." " That's right, yep." "So this is where it's coming through here - the gateway?" " Yes." " The sea bursts through this narrow opening." "It's like someone turning a power hose onto these rocks." "When you've got a really big storm, a wave would actually fill it right up, just tearing through this gap." "Just a great wall of water coming through there, plucking off boulders and hurling them backwards." "It's making me uncomfortable standing here in the firing line of that gateway." "Yes, perhaps we should move on!" "These boulders have been tossed like pebbles." "It's just one of the ways waves have transformed this landscape." "This coast is strewn with clues, clues which reveal the terrifying power of the sea." "You just have to know where to look." "Across the loch from one of the UK's biggest oil terminals," "I'm on the hunt for signs of a cataclysmic event which hit these islands thousands of years ago." "'Apparently the evidence is hidden in the peat banks of Sullom Voe.'" "Lovely beach you've brought me to here, Adrian." "'Geomorphologist Adrian Hall is going to show me what to look for.'" " This is peat." " Well, I know that." "It's got a wonderful environmental history locked in there." " We've got the modern vegetation here." " That's where we are today." "And then here we've got the dried-out peat and then clear layers in the peat." "And then when we get down to about here, we've got a very, very clear change." "It's mainly sand, but as you can see there are lumps of gravel." "Yeah, a sudden change of colour, isn't there?" "And texture." "But even more striking are these lumps of peat which clearly have been torn up from some pre-existing peat bank." "Let's just have a look at that." "The sand layer is really quite thick with marine organisms in it, so you've got to have a process that brings this material from the sea bed and up onto land." " So what it is?" " There's only one thing that can produce deposits of sand" " 20 metres above sea level and that's a tsunami." " A tidal wave?" "!" "A tidal wave." "The sand layer buried in this peat is evidence of a tsunami that hit this coastline 7,000 years ago." "It was caused by a gigantic underwater avalanche on the continental slope off Norway." "When a mass of sediment collapsed onto the sea bed, it generated killer waves destined for Shetland 250 miles away." "Well, the first hunter-gatherers were already on Shetland 7,500 years ago, so we've got to imagine this as a broad open valley, the sea far, far out there, and then suddenly on the horizon," "there would be a wall of water and it would be moving very rapidly." "So it funnelled down Sullom Voe and got constrained between the two shores." "it would build and grow until eventually you were looking at a wall of water 20m high." "And then it would break and surge forward into this area, carrying the debris and hurling it against the land." "The low lying parts of Shetland would have been completely overwhelmed." "This ancient tsunami reached as far south as the English border." "The tsunami which struck these islands was a freak event, but the waves being generated by North Atlantic weather patterns are not and they can be just as ferocious." "Big waves are going to reach further inland." "Life on the edge could get a lot more precarious." "This coast might be inhospitable but that hasn't deterred generations of invaders." "The Vikings landed here and sited their capital at the harbour village of Scalloway." "These islands do feel very different from the rest of Scotland." "They were under Norwegian rule right up until the 15th century." "The ties to Norway are very, very strong." "They were never stronger, though, than during the Second World War." "In 1940, Nazi Germany invaded Norway." "Shetland's neighbour needed help and the North Sea offered a lifeline to Norwegian resistance fighters." "The islands became the base for a daring, secret operation - the Shetland Bus." "The "bus" was a fleet of fishing boats which smuggled people out and agents in to occupied Norway." "Many lives were saved and many lost." "The islanders have never forgotten the sacrifice of these men." "The names, the age, when they died and the boats that they were on." "23, 28, 21, 21." "Just wee boys." "Just boys." "'Karen Anderson's father was one of the Norwegian sailors who survived." "'At 23 years old, Kare Iversen risked everything for his homeland.'" "So how did your dad get involved in that story?" "Dad escaped from Norway in 1941 in his father's boat and they came across to Shetland and he was approached to see if he was suitable for the Shetland Bus and he was." "Most of their missions were carried out in winter, when the dark nights provided some cover for the 500-mile round trip across the North Sea to Norway." "Ammunition was stored at Scalloway Castle while resistance fighters and refugees found shelter with the locals." "The men became heroes." "After the war, their bravery was celebrated in the Norwegian feature film The Shetland Gang." "It was very dangerous because they didn't know what they were going across to Norway to face." "The weather was against them and the Norwegian fishing boats they were using weren't big." "He said if he was captured, that they all had a cyanide pill to take, rather than be interrogated by the Germans." "Losses were heavy - over 100 died in storms or German attacks." "But many lives were saved." "By the end of the war, more than 350 refugees had been carried to safety." "How much does the story of the story of Shetland Bus" " still mean to people in Shetland?" " Oh, a great deal." "I'm very proud of my dad." "Really." "I mean, I cannae say in words how I feel about what...not only him, but what other Norwegian boys did." "It's part of Scalloway's history, always will be." "These islands have provided safe refuge to many." "Its rich, unspoilt coastline is a haven for wildlife." "Seals are at home in these well-stocked waters and there's a large population of otters." "'I'm catching a ride with skipper Tom Jamieson 'who knows the seas off this coast.'" " All right, Tom." " Hello, Neil." "What kind of wildlife is supposed to be out here?" "We've had minke whales in." "And also killer whales." "We never used to see killer whales - there are more of them around now." "These waters aren't just teeming with wildlife." "North Sea shipping passes the southern tip of Shetland on its way to the Atlantic." "At Garths Ness, one vessel's journey would end in disaster." "At 5.10am on the 5th January 1993, the coastguard received a distress call from the crew of an oil tanker whose engines had broken ten miles off the coast of Sumburgh Head." "Gusts of up to 97 miles an hour were driving the oil tanker Braer ashore." "After a six-hour struggle, she ran aground." "84,000 tonnes of toxic crude oil spewed out into the sea, creating the worst environmental disaster ever to hit the British coast." "Coastguards managed to winch the crew to safety, but Shetland's wildlife was not so lucky." "Seabird colonies, seals, shellfish, fish hatcheries, grazing bays were all badly polluted." "Shetland braced itself for the worst." "The storm raged for almost a month, seriously hampering the clean-up campaign." "But the brutal power of the waves started to work in the islanders' favour." "Ultimately the sea's power broke up the oil and helped clean up the shores." "The sheer force of the pounding water acted like a giant washing machine, churning up the oil and dispersing it out to sea." "These islands are constantly at the mercy of the elements, but on this occasion, nature came to the rescue." "Shetland may feel like a different world to the mainland, but to some people, it IS the mainland." "24 miles out to sea is Fair Isle." "Three miles long and a mile and a half wide, you're only ever three-quarters of a mile from the sea here." "This is home to fewer than 80 people, many drawn here by a way of life that is hard to find anywhere else in the UK." "SHIPPING FORECAST:" "Thundery rain or showers." "Moderate or good." "Fair Isle, south four or five, occasionally six becoming variable three or four." "Rain or showers - moderate with fog patches, occasionally good later." "'I think lots of people will know of Fair Isle 'from the shipping forecast." "'I'm Dave Wheeler.'" "'I'm a weather observer on Fair Isle' doing regular weather observations every hour of the day from six in the morning till six at night for 35 years now." "12.4." "0.1mm of rain." "People do ask me quite frequently what the weather is going to do." " Tomorrow will not be too bad a day." " Boat tomorrow?" "Yeah, it looks like a boat day." "'I hope I can give them a good service.' OK, bye!" "'If I'm wrong, they don't hold it against me.'" "Hello, puss!" "This is the sunshine recorder." "Hmm, no sun." "Surprise, surprise!" "And we said, what, visibility?" "Hmm, 50 metres visibility." "Dense fog." "We hope for a better day tomorrow." "SHIPPING FORECAST:" "Fair Isle, south four or five, occasionally six, moderate with fog patches, occasionally good later." "Over 67 different islands make up Orkney, or, as they were known to their Viking rulers, Orkneyjar - seal islands." "Nowadays the island-hopping lifestyle of the locals has led to a unique claim to fame." "People come from all over the world to fly less than two miles between Papa Westray and Westray." "Here we are then, wheels up on the world's shortest scheduled flight." "I have to say, it's all going very well so far." "This journey usually takes a couple of minutes, but it's been done in just 69 seconds when it made the Guinness Book of Records." "Somebody once told me that the most dangerous part of flying is taking off and landing, but that's all this flight is - a take-off and a landing." "This flight might seem a little extravagant, but the £14 fare is subsidised because it's an important link for these remote communities." "And we're down!" "Tourism certainly adds to the traffic around Orkney but 260 years ago, it was trade that dominated these waters and navigation was a nightmare." "These islands, like the rest of the British Isles, were surrounded by largely uncharted waters." "But in the 18th century, that was all about to change." "Over in Kirkwall," "Mark Horton is discovering how one Orcadian made our seas safer." "In 1743, a curious advertisement turned up in newspapers and coffee houses throughout Britain." "A local schoolmaster from here in Orkney, Murdoch McKenzie planned to make a really detailed chart of these treacherous waters and was desperately needing sponsors to help pay for his ambitious project." "Orkney was the hub for north Atlantic trade routes, but hazardous tides and uncharted seas meant shipwrecks were common." "With finance from traders and merchants," "Murdoch McKenzie set about charting Orkney's coast in ways that would revolutionise mapmaking around the world." "'Local sailor Sandy Firth has studied McKenzie's pioneering work." "'He even owns a rare copy of his original survey.'" "Is this the actual folio of charts?" "Yeah, it's one of them, the bound edition of McKenzie's survey." " 1750." " 1750." "McKenzie was the first man to start putting in these symbols." "Now they indicate the nature of the bottom of the sea." "He gives you the state of the tide at different times and the direction of it." "And no-one had bothered to do that up until now." "No and McKenzie's little symbols that you'll see here are still used to this day in admiralty charts." "I've got a good idea." "I want to survey this bay and lets see if we can actually make a map using the same methods as McKenzie used himself." "'McKenzie devised a method of charting any position at sea 'by using fixed reference points on land.'" " There we go." "Spot on." "Around 69 degrees roughly." " 69." "'McKenzie realised it wasn't only essential 'for sailors to know where they were at sea 'but also what hidden dangers were lurking under the water." "'He gathered samples from the ocean floor using a rope and lead weight 'covered in tallow - animal fat.'" "The tallow should pick up what's on the bottom, shouldn't it?" " There's two bits of leather there." " Two fathoms." " Two fathoms." "And..." " Looks like mud on the bottom, doesn't it?" " Genuine mud." "Just like McKenzie did it." "Murdoch McKenzie's methods changed the way we view the underwater world." "Over 260 years after he first charted the coast of Orkney, the science of surveying he did so much to inspire has advanced to this." "This coastguard vessel is equipped as a state-of-the-art survey ship." "'Rob Spillard is the officer whose mission is to boldly go' where the charts may not necessarily be reliable." "You can see just to the south of this island here, there's a 26 metre contour." "We had an incident just a few days ago." "A vessel grounded just off that island we can see out there." "It's done about a million pounds worth of damage to the vessel." "They put in a note that 26m was wrong and it's shallower." "They claim to have grounded at 11m and so we're here today to try and prove whether the chart is right or wrong and make it safer for others making the same passage." "This is real detective work." "There's an obstruction hidden out there that's already wrecked one vessel." "Next time, it may be fatal." "So how do you actually measure depth in the 21st century?" "As opposed to doing it with a lead line and a linesman and measuring one depth every minute, we can measure several thousand depths every second." "We do that by sending out pings of sound into the water underneath the ship and then listening for the return." "The quicker the echo, the shallower the water." "By measuring return data, the team can produce a remarkably clear picture of what lies below the surface." "This German U-boat from the First World War was discovered on the sea bed just off Orkney." "But today we're looking for something much nearer the surface - an obstruction that's caused serious damage." "The ship's sailing back and forth over the suspicious area, gathering thousands of depth readings." "So we're coming past where the vessel ran aground." "If you look at this screen here, you can see all the rockiness on the starboard side as we get close to the rock so you should be able to see the rock as we get close to it." "As we go over top of the rock." "So the depth under the keel is that figure up there." "It is, yeah." "As we get closer to where the vessel grounded, that figure will decrease as the sea bed comes up to meet us." "When the altitude figure here goes to about five metres, that's when we need to put on our life jackets." "So the obstruction could still be out there?" "Yes, it is quite touch and go actually." "'The soundings are showing 'that the charted depth of 26 metres is wrong." "'But what we don't yet know is 'just how close below us these rocks are lying.'" "12...11..." "We should be keeping our fingers crossed." "Ten..." "This is terrifying!" "We've gone down to nine." "RAPID BEEPING" "'And then we find it!" "'Just 7.5 metres below us, 'a massive rock much closer to the surface than charted 'and a major risk to shipping.'" "If we'd gone over that at very low tide, we'd have been very, very close to touching it." "So that's the actual structure of the rock." "You can see the crinkles and crevices." "This area's made of rock." "It's amazing." "'We're about to make a new mark on the chart of our coastal waters." "'I'm sure Murdoch McKenzie would have approved!" "'" "Really what's so amazing is that we could do it in an afternoon." "If you'd had to do this with a lead line, it would have taken a long, long time to do." "So this new technology not only save money" " but saves lives as well." " Absolutely." " A good day's work." " You did very well, actually." "Shipwrecks might seem like the end of the line, but folk up here learn to make the most of whatever the coast provides." "Wrecks have always fascinated me - huge sculptures of rusted steel forms, which have kind of been torn apart and thrown up on the coast." "I'm Sam McDonald." "I'm a marine wildlife sculptor really." "The sea has always been a constant inspiration to me." "I love it because you go into another world." "The rust is an amazing colour - you get so many different hues and tones that are very beautiful, especially when contrasted with the ultramarines and blues underneath the water." "Then every now and again you'll get flashes of life with the fish shoals." "Really my work is about me sharing a moment with nature and then trying to recapture it in metal." "'I did once count how many hammer blows there were in a fish,' and there were 987 in one of these fish." "The weight and ugliness of a wreck is kind of contrasting with the fish themselves, so I like the fact that something so powerful has ended up rotting away on the bottom of the sea, with these fish darting in and out of it." "Living and working with this glorious, fertile landscape runs through the DNA of Orkney folk." "People have been living here since Neolithic times." "Wherever you go, there are signs of ancient cultures." "Over on the Bay of Skaill lies the village of Skara Brae." "Welcome to island life...3000 BC." "This place was occupied continuously for 600 years and then for reasons that we don't know and don't understand, it was abandoned forever." "The village is set down into a hollow." "It's dug in to get out of the wind." "Now this is rare privileged access." "Nobody really gets in here any more." "When you get in, there is a sense in which it's cosy." "The builders really understood how to make the most out of this building material." "Cos the walls are curving up so that they're coming over like an igloo shape." "This is a big central hearth here." "In the winter months, there'd be a big fire here." "These areas are for sleeping in." "There's a recess back there for personal belongings, and all of the houses have a dresser like this one." "So perhaps there'd be other personal belongings or special objects would be on display here." "Before Stonehenge, this village was here." "That's how old it is." "Of course, the most intriguing mystery of this place are the people who lived here." "We know so little about them." "We don't know what language they spoke." "We don't know if they followed a religion and, most of all, we don't know why they left." "That's the big mystery of Skara Brae to me." "There are many things that might attract you to live on Orkney." "One is the crime rate - it's the lowest in Scotland." "But local fishermen are still the victims of regular raids on their lobster pots." "The prime suspect has a reputation as a very flexible thief." "Miranda Krestovnikoff is on the trail of the elusive octopus." "Spotting an octopus in the sea is harder than finding that famous needle in a haystack." "They're shy and clever animals and remarkably good at hiding, but here in Orkney is one of the best places in the UK to find them." "That's because these seas are full of their favourite food - lobster." "I'm on the hunt for an octopus with Daniel Wise, a marine biologist who's been studying the island's waters." "He reckons the best place to see this slippery customer is a little-known dive site called Inga Ness, but it's not going to be easy." "Octopus are really clever animals." "They're an active mobile hunter, they can change the colour and texture of their skin to suit the environment that they're in." "They can also squeeze into the smallest of crevices and holes." "So if they don't want to be found, they won't be found." "Let's go." "Inga Ness is a rock stack in the water, a peak that time has weathered flat so now it barely stands proud of the tide mark." "Below the waves though, this pinnacle shows its true dramatic nature, with a sheer drop to the ocean bed." "'Our first sighting is a lion's mane jellyfish." "'This animal has a sting in its tail 'and tentacles that can grow as long as 30 feet.'" "Miranda, watch for its tentacles cos they will sting and it is painful." "It's so beautiful." "'Smooth rock paves the sea floor, giving the landscape a barren feel." "'But the lack of vegetation 'makes it easy to find our first lobster pot.'" "I don't think there's anything in this one unfortunately." "Just carry on a bit." "There might be one later." "Yeah, I'm sure we'll find some more." "'Not far from the empty pot though is an unexpected surprise - 'a wolf fish.'" "You normally see them in a crevice or a hole." "They are quite hard to spot." "And this one doesn't look that big." "Is this a juvenile?" "That's right." "They do grow a lot bigger." "Look at those fearsome teeth!" "'Trying to hide amongst the seaweed, a lobster is on the prowl, 'an unusual sight before sundown.'" "See how the one claw is larger than the other claw?" "That claw is called the crushing claw and it is used to crush prey." "I guess we might have disturbed him from his lair, maybe given him a fright." "'It's soon clear though 'that it was something else keeping this lobster on its toes." "'Nearby, almost perfectly camouflaged against the rocks, 'an octopus sits quietly.'" "It's so beautiful." "If you get up close, you can see as it's moving, it's just gently changing colour every time it moves." "It is blending in absolutely beautifully with the background." "'Special cells in the skin called chromatophores 'make the octopus a master of disguise." "'These change colour and texture in a matter of seconds, 'allowing this elusive creature to blend in with his surroundings 'and escape detection." "'They can also squeeze through the smallest of holes." "'Only metres away, we catch an octopus red-handed.'" "That's beautiful!" "It's like liquid, it's so fluid." "'It's sneaked into a pot and is eyeing up a lobster, 'planning to turn it into a gourmet dinner." "'The beak of the octopus is its only bone-like structure." "'It bites through the hard shell of the lobster 'and injects venom to paralyse its victim." "'But as troublesome as these master robbers may be for fishermen, 'it's hard not to have a sneaking admiration for their ingenuity.'" "The sea has been a source of rich pickings since the dawn of time, and at Billia Croo, they're exploiting it 21st century style." "It's amazing the things you find in unexpected places." "In that wee concrete shed, they're wiring up for an electrical revolution that might help save the planet." "Ever felt like you're being watched?" "Up here, they're setting their sights on energy from the sea." "'A new generation of islanders, like Barry Johnston," " 'see their future in marine energy.'" " Hello there, Neil." " Hello, Barry." " Nice to meet you." " You too." "Could you have got a more remote location?" " Not really!" "What is the camera watching?" "At the moment the camera's watching a test area out here in the ocean, and the purpose of this test area is to try out new tidal and wave energy systems." "What is it about the seas around Orkney that makes them the best for wave energy?" "They're really just so exposed." "There's no land masses between us and America so it's so open and the waves are so powerful." "In the seas off Orkney lies the potential for a substantial supply of green energy." "This machine is designed to convert wave motion into electricity." "It's called Pelamis and it's one design of what wave power could look like in the very near future." "It's being tested here in some of the roughest waters imaginable." "How does Pelamis actually generate power?" "Pelamis is a long cylindrical structure with hinged joints down its length." "Those hinged joints move in the wave action and are resisted by high pressure hydraulic cylinders." "So it's actually the way that the Pelamis resists the waves" " that creates the electricity?" " That's right, yes." "The key to this design is the seesaw motion at the joints." "As each wave passes, oil is forced through hydraulic motors linked to generators to produce electricity." "What about on a calm day like today?" "Would Pelamis still switch on light bulbs with just that amount of action?" "Absolutely." "Pelamis is designed to be efficient in seas like these, so there's lots of energy even on a day like this." "It's not just the waves that make Orkney good for marine energy." "Here they can measure the amount the power systems produce as they connect them to the national grid at this substation." "The testing centre here in Orkney plans to be busy evaluating new devices." "Soon, this single machine could generate electricity for 500 homes, maybe the first drops in a new ocean of green energy." "So far, we've travelled over 150 miles on our journey south from Shetland." "The final stretch takes us over the water again to Hoy." "Hoy means "high island" and that's exactly what this is." "These sea cliffs are some of the most impressive in Britain." "Earlier today, two climbers set out to tackle Orkney's most famous landmark." "The Old Man of Hoy stands 450 feet tall on the shores of the Pentland Firth." "This magnificent sea stack used to be attached to the headland, but the elements have slowly eroded the soft red sandstone to create this solitary pinnacle." "No-one knows how much longer the Old Man will stand before he falls into the sea." "This morning, driving rain and strong winds greeted Andy Cave and fellow climber Simon Nadin at the start of their ascent." " Are you excited, Simon?" " 'In this weather, 'the slippery unstable rock is even more dangerous.'" " Not looking in its best conditions, I must admit." " Yeah." "Better than being in the office though." " Maybe." " Definitely." "But despite the conditions, they've decided to give it a go." "I'm off to catch up with the guys to find out what makes this stack the one every climber wants to bag." "Simon and Andy have been climbing for three hours." "The weather has improved and their chances of reaching the top are looking better." " Are you all right there?" " Yeah." " How was that pitch?" " I've got a bit of a lather on." "You've got a bit of a lather on there, kid!" "I reckon we're gonna have midges all the way up." "We can't handle the midges but we're coping with the sea stack." "'Hello, Andy." "It's Neil, can you hear me?" "'" "All right, Neil, how's it going, mate?" "I'm fine but then I'm on the mainland." "How's it been going so far?" "We were a bit worried really because it's been raining and in the mist it was very easy to slip off." "Our hands were covered in green slime and our feet were covered in bird poo so it was just horrible, very insecure." "But I think now we are less worried and just concentrating on the job really." "Right, I'll let you crack on." "The Old Man was first conquered in 1966." "It was a three man team " "Chris Bonington, Tom Patey and Rusty Baillie." "Even Everest had been climbed many years before anyone knocked off this monster and it was such a success that the climb was recreated the following year." "That time, the TV cameras were in attendance." "Covering the ascent for television was as challenging as climbing the Old Man himself." "# Ain't no mountain high Ain't no valley low" "# Ain't no river wide enough, baby... #" "Everything had to be brought from the mainland." "30 tonnes of equipment were hauled over the moors to create an outdoor studio." "But as the transmission date approached, so did a westerly gale." "The temporary studios were wrecked." "But the team rallied round." "# No wind, no rain" "# Or winters cold can stop me, baby... #" "It was the first live programme of its kind." "Over 20 million viewers tuned in over three nights to watch Chris Bonington and his team make nail-biting television history." "Somewhere there are four climbers, four radio cameramen." "There you can see the radio camera men on the gallery." "This is the hardest move on this, I think." "I have somehow got to turn round here and I've got rather a bad hand-jam right inside the crack." "I've got to swing right round." "Climbing the Old Man of Hoy today is just as demanding and no less dangerous." " That's nice." " Nice finish." " Yes, very good." "That's stunning." "That's moving." " Is it?" " Yeah." "Stay up there, I'll come up in a bit." "It took the original team two days to find a route to the summit." "Climbing in their footsteps, it's taken our guys around five hours." "Nice one, excellent." "I'm absolutely stunned." "I can't believe you did it, given how miserable it was when you started out this morning." "I know." "We're pretty surprised too but it's a privilege to be up here, it really is." "We have to show respect for Chris Bonington and co who made the first ascent, which has enabled us to reach this point." "We've climbed all over the world but there's not many places as cool as this." "Up here in the Northern Isles, you can't help but notice that life is defined as much by the sea as it is by the land." "People here have to learn to be resilient." "Life on the edge is precarious but often exhilarating." "Subtitles by Red Bee Media Ltd" "Email subtitling@bbc.co.uk"