0:00:02 > 0:00:04My name's Steve Backshall...
0:00:06 > 0:00:09..and this is Deadly Pole To Pole.
0:00:09 > 0:00:11Oh!
0:00:11 > 0:00:13From the top of the world to the bottom...
0:00:13 > 0:00:15Whoa! Ha-ha.
0:00:15 > 0:00:17..deadly places,
0:00:17 > 0:00:18deadly adventures
0:00:18 > 0:00:20and deadly animals.
0:00:21 > 0:00:24And you're coming with me every step of the way.
0:00:26 > 0:00:27Argh!
0:00:30 > 0:00:32This is Alaska.
0:00:32 > 0:00:33It's the largest state in America
0:00:33 > 0:00:37and the scale of it is simply impossible to comprehend.
0:00:37 > 0:00:41You can fly for hours and below you see nothing but lakes,
0:00:41 > 0:00:42mountains and forests.
0:00:42 > 0:00:46For lovers of the wild world, this the last frontier.
0:00:48 > 0:00:51Alaska is the most northerly state in America.
0:00:51 > 0:00:54The top is just 1,300 miles from the North Pole.
0:00:54 > 0:00:58It's the next wild wonderland in line as we continue south.
0:00:59 > 0:01:02We see the largest land predator hunt...
0:01:03 > 0:01:07..get a dazzling display from an ocean giant,
0:01:07 > 0:01:09and explore where no-one's been before.
0:01:15 > 0:01:18For the first time on Deadly we're not looking for an animal
0:01:18 > 0:01:21but a feature of Alaska itself,
0:01:21 > 0:01:23a deadly force of nature.
0:01:23 > 0:01:26So unstoppable that it's shaped the world we live in.
0:01:26 > 0:01:28It's of such a size and scale,
0:01:28 > 0:01:30the only way to appreciate it is from the sky.
0:01:31 > 0:01:35We're pulling up at what appears to be a vast white-water river.
0:01:35 > 0:01:38But this is in fact a river of ice.
0:01:38 > 0:01:39It's a glacier.
0:01:39 > 0:01:42Alaska's home to more glaciers than the whole of the rest
0:01:42 > 0:01:45of the inhabited world put together.
0:01:45 > 0:01:49About 75% of the world's fresh water resides in glaciers
0:01:49 > 0:01:53but even though these are incredibly important life-giving forces,
0:01:53 > 0:01:55they can also be deadly.
0:01:58 > 0:02:02Constantly moving glaciers have the power to sculpt mountains,
0:02:02 > 0:02:06carve valleys and give birth to giant icebergs.
0:02:08 > 0:02:10Made up of millions of tonnes of ice,
0:02:10 > 0:02:13they plough through everything in their path.
0:02:26 > 0:02:29These mighty cliffs of ice are called ice-falls.
0:02:29 > 0:02:33They're sort of like the glacier's equivalent of a waterfall.
0:02:33 > 0:02:35It's where the ice comes over areas that are so steep
0:02:35 > 0:02:38that they simply tumble down, they collapse over each other.
0:02:38 > 0:02:42This is one of the most dangerous places you can possibly be
0:02:42 > 0:02:43in the mountains.
0:02:43 > 0:02:46If one of these huge, great big towers of ice goes,
0:02:46 > 0:02:48it is an unstoppable force.
0:02:48 > 0:02:50But safe as we are up here,
0:02:50 > 0:02:53you can't learn much about its deadly side from the sky.
0:02:53 > 0:02:57We're going to take a journey into the icy heart of this glacier,
0:02:57 > 0:03:01into a dangerous and challenging world where anything could happen.
0:03:03 > 0:03:07As a mountaineer, I've spent many months in environments like this,
0:03:07 > 0:03:10camping out on the ice as it creaks and groans around you,
0:03:10 > 0:03:14but where we're going nobody will have ever been before.
0:03:16 > 0:03:20It looks like one big, white, solid object.
0:03:20 > 0:03:24A glacier is almost a living, moving thing,
0:03:24 > 0:03:27All of this forms way up high in the mountains
0:03:27 > 0:03:29in a place called the ice field,
0:03:29 > 0:03:33so snow will accumulate over centuries and centuries
0:03:33 > 0:03:36and it gets compacted by its own weight
0:03:36 > 0:03:40and turns into ice and that ice starts to flow down like a river,
0:03:40 > 0:03:44forming these incredible ice-falls and great sheets of ice.
0:03:45 > 0:03:48But we're not just interested in what goes on at the surface.
0:03:50 > 0:03:52All of the ice on the surface of the glacier
0:03:52 > 0:03:55is constantly heated by the sun
0:03:55 > 0:03:57and forms little streams like this,
0:03:57 > 0:04:00which eventually run into big rivers.
0:04:00 > 0:04:04Now, these rivers create an enormous amount of water
0:04:04 > 0:04:06and that water has to go somewhere.
0:04:06 > 0:04:10Eventually, it finds a weak point in the glacier
0:04:10 > 0:04:12and it burrows down into a whirlpool...
0:04:13 > 0:04:15..called a moulin.
0:04:15 > 0:04:19This is the gateway to the guts of the glacier.
0:04:19 > 0:04:22It's an incredibly frightening place and believe it or not,
0:04:22 > 0:04:24that's where we're going.
0:04:25 > 0:04:28So the team and I get to work setting up a rope system
0:04:28 > 0:04:31to allow myself and Johnny to climb down into the moulin.
0:04:34 > 0:04:37Whilst they are very dangerous places,
0:04:37 > 0:04:40moulins are incredibly exciting
0:04:40 > 0:04:41and you can say with confidence
0:04:41 > 0:04:44that no-one has ever been down this before
0:04:44 > 0:04:47because the place itself is always changing.
0:04:47 > 0:04:49It's never been like it is right now
0:04:49 > 0:04:50and that, to me,
0:04:50 > 0:04:53is the most exciting thing about this environment.
0:04:56 > 0:04:59After some final checks, and with the ropes in place,
0:04:59 > 0:05:01it's time for me to head off into the unknown.
0:05:03 > 0:05:05I have no idea what we're going to find
0:05:05 > 0:05:08cos no-one's been down into this before but it's going to be loud,
0:05:08 > 0:05:11it's going to be wet
0:05:11 > 0:05:13and, of course, it's going to be very, very cold.
0:05:15 > 0:05:19I'm trying to find a dry ice cave, so cameraman Johnny can join me.
0:05:27 > 0:05:29The second I leave the sun behind,
0:05:29 > 0:05:32the temperature drops below freezing.
0:05:33 > 0:05:36Holy moley.
0:05:36 > 0:05:37OK, so, for the first time,
0:05:37 > 0:05:40I can kind of see what it is I'm taking on.
0:05:40 > 0:05:43The waterfall has cut its way
0:05:43 > 0:05:46into a massive cataract.
0:05:47 > 0:05:51It's a tunnel that goes right down to the very base of the glacier
0:05:51 > 0:05:54and just below my feet here there's a cave.
0:05:54 > 0:05:56Wow!
0:05:56 > 0:05:57This is so awkward.
0:06:01 > 0:06:03I can see right inside.
0:06:05 > 0:06:07It's unbelievably beautiful.
0:06:08 > 0:06:11Well, I guess the next move is to get you down here, Johnny.
0:06:17 > 0:06:20I'm not sure how far this cave goes.
0:06:20 > 0:06:23It's an incredible deep, deep blue colour.
0:06:23 > 0:06:25There's this ice here
0:06:25 > 0:06:28that's formed over hundreds of years
0:06:28 > 0:06:30and it's incredibly solid.
0:06:30 > 0:06:33I'm not sure how far this is going to go.
0:06:33 > 0:06:35It's like tiptoeing on cold glass.
0:06:35 > 0:06:38My metal crampons skid about on the ice.
0:06:38 > 0:06:40This is incredibly beautiful.
0:06:42 > 0:06:45It's like a little fairy cavern.
0:06:45 > 0:06:47It's kind of easy to get carried away
0:06:47 > 0:06:48with the beauty of the place
0:06:48 > 0:06:50and forget where you are,
0:06:50 > 0:06:53but I guess the nightmare would be
0:06:53 > 0:06:55if the glacier continued to move
0:06:55 > 0:06:57and the walls just closed in.
0:06:57 > 0:07:00You'd get squashed like a mosquito.
0:07:00 > 0:07:04Myself and Johnny travel deeper and deeper inside the glacier
0:07:04 > 0:07:08to see how far we can travel down this unexplored cavern.
0:07:08 > 0:07:10Oh, ho-ho!
0:07:10 > 0:07:11There's a big drop down there
0:07:11 > 0:07:15but it looks too thin for a person to go through.
0:07:17 > 0:07:18I think that's a dead end.
0:07:29 > 0:07:32Well, can't carry on through the dry part of the cave,
0:07:32 > 0:07:35so the only way to continue exploring
0:07:35 > 0:07:38is down there beneath the waterfall.
0:07:38 > 0:07:40There's no way the cameraman can come with me.
0:07:40 > 0:07:42It's much too wet, the camera would die,
0:07:42 > 0:07:44so I would have to go down there on my own.
0:07:53 > 0:07:57But that is a whole new level of risk and challenge.
0:07:57 > 0:07:59I'll need protective clothing,
0:07:59 > 0:08:02but even that won't completely keep the icy water at bay.
0:08:03 > 0:08:06OK, I'm all prepared for my trip into the underworld.
0:08:06 > 0:08:08I've got my waterproof suit on,
0:08:08 > 0:08:11I've also got this camera
0:08:11 > 0:08:14which we usually use for filming underwater
0:08:14 > 0:08:16and as soon as I get over the edge and I'm into the waterfall
0:08:16 > 0:08:18I'll lose contact with the rest of the crew,
0:08:18 > 0:08:20so I've got a radio to be able to talk to them
0:08:20 > 0:08:23and I can't put it off any longer.
0:08:23 > 0:08:26This is going to be seriously cold.
0:08:26 > 0:08:30That is the understatement of the century.
0:08:30 > 0:08:33The glacial meltwater thunders into the blue depths
0:08:33 > 0:08:36and in a few minutes it's going to be crashing over me.
0:08:41 > 0:08:43I'm going to get absolutely hammered here.
0:08:48 > 0:08:49Whoa.
0:08:49 > 0:08:52This looks absolutely brutal.
0:08:52 > 0:08:55I've got two separate falls coming in.
0:08:55 > 0:08:57The big one over there I'm going to be able to stay clear of
0:08:57 > 0:08:58for most of the way.
0:08:58 > 0:09:00That one's going to hit me
0:09:00 > 0:09:02within a few metres...
0:09:03 > 0:09:07..and the water is going to numb my brain and my fingers
0:09:07 > 0:09:10and my whole body will start to shut down really quickly.
0:09:35 > 0:09:38This would have to be one of the most hostile places
0:09:38 > 0:09:40you can ever be in.
0:09:41 > 0:09:45This is a place that human beings are simply not supposed to be.
0:09:48 > 0:09:50I'm looking down
0:09:50 > 0:09:53to the very bottom of a glacier,
0:09:53 > 0:09:58an enormous, moving river of ice.
0:09:58 > 0:10:01If I didn't have my drysuit,
0:10:01 > 0:10:03I wouldn't last seconds here.
0:10:04 > 0:10:07The water is only just above freezing
0:10:07 > 0:10:09and thundering down around my ears.
0:10:15 > 0:10:18Steve, are you OK down there?
0:10:18 > 0:10:19Uh...
0:10:19 > 0:10:20Uh!
0:10:23 > 0:10:25I'm not sure if he's going to hear it.
0:10:26 > 0:10:28Uh.
0:10:28 > 0:10:30Oh, my fingers!
0:10:30 > 0:10:32I can't feel my fingers.
0:10:32 > 0:10:33Is he coming back, Johnny?
0:10:37 > 0:10:39Oh!
0:10:39 > 0:10:40Whoa!
0:10:43 > 0:10:46It's such an incredibly beautiful place...
0:10:47 > 0:10:51..but it's almost too frightening and too overwhelming to appreciate.
0:10:55 > 0:10:57I don't think I should go on any further.
0:10:57 > 0:10:59I think it'd just be too dangerous.
0:11:01 > 0:11:04And look at all that water thundering down below me.
0:11:06 > 0:11:08I think, if I tried to head down there...
0:11:10 > 0:11:11..I wouldn't make it.
0:11:15 > 0:11:19OK, I need to start climbing back up now.
0:11:23 > 0:11:24One last ledge.
0:11:26 > 0:11:29But the water has frozen my fingers solid.
0:11:30 > 0:11:34I can't get back onto the ropes to start climbing out.
0:11:34 > 0:11:36It seems things could be about to go bad.
0:11:37 > 0:11:39But then finally I get it together
0:11:39 > 0:11:42and start to escape the waterfall,
0:11:42 > 0:11:45very glad to see sunlight again.
0:11:45 > 0:11:46Come on!
0:12:00 > 0:12:06That was probably the most hardcore thing I've ever done on Deadly.
0:12:06 > 0:12:09It's going to be hours before I can feel my fingers again.
0:12:11 > 0:12:13I am
0:12:13 > 0:12:14totally
0:12:14 > 0:12:16smashed...
0:12:17 > 0:12:20..but there's no doubt that
0:12:20 > 0:12:23places like moulins
0:12:23 > 0:12:25are a lethal environment.
0:12:27 > 0:12:29Definitely deadly.
0:12:31 > 0:12:34Crevasses and moulins are gateways to the abyss.
0:12:35 > 0:12:37A glacier can shift
0:12:37 > 0:12:39and collapse without warning.
0:12:39 > 0:12:43They're an unstoppable force that can carve mountainsides,
0:12:43 > 0:12:45bulldozing everything in its path.
0:12:45 > 0:12:47A force of nature that's...
0:12:47 > 0:12:49Deadly.
0:12:53 > 0:12:55Alaska's so huge and has so few roads,
0:12:55 > 0:12:58that to really explore, you need to fly.
0:13:01 > 0:13:05And in a plane that doesn't have to rely on having a runway to land on.
0:13:07 > 0:13:11We're heading to Admiralty Island on the southeast coast.
0:13:12 > 0:13:16And we're here to find a real wild record breaker.
0:13:16 > 0:13:19The largest land carnivore, the grizzly bear.
0:13:20 > 0:13:22With their cousin the polar bear,
0:13:22 > 0:13:24this is the largest carnivore on Earth.
0:13:25 > 0:13:29The record breaker was a brown bear who weighed over a tonne,
0:13:29 > 0:13:31and standing upright was double my height.
0:13:35 > 0:13:36So this is it.
0:13:37 > 0:13:41With approximately one bear for every square mile here,
0:13:41 > 0:13:45every single step we take now is a step further into bear country.
0:13:47 > 0:13:51The floatplane flies off, leaving the crew and I behind.
0:13:51 > 0:13:52And there he goes.
0:13:52 > 0:13:54From here on in, we are on our own.
0:13:54 > 0:13:57Just us and an awful lot of bears.
0:13:57 > 0:14:00This island has one of the highest concentrations of grizzlies
0:14:00 > 0:14:01found anywhere.
0:14:01 > 0:14:05And at this time of year, it's all about hunting salmon.
0:14:06 > 0:14:09Once at the inlet the bears are already putting on
0:14:09 > 0:14:10quite a performance.
0:14:12 > 0:14:13- BEARS GROWL - Whoa.
0:14:13 > 0:14:16There are two young bears doing what
0:14:16 > 0:14:19a lot of young mammals will do at this age,
0:14:19 > 0:14:23just play fighting, trying out their skills on each other.
0:14:23 > 0:14:28They're standing up like a couple of big, furry wrestlers.
0:14:28 > 0:14:30They're learning how far they can go,
0:14:30 > 0:14:32how strong they are
0:14:32 > 0:14:35and all of these skills are going to be put to use, catching prey.
0:14:38 > 0:14:41And you can certainly see evidence that there is
0:14:41 > 0:14:44a lot of food around cos the bears aren't the only predators here.
0:14:44 > 0:14:47There are lots and lots of bald eagles
0:14:47 > 0:14:49lining the side of the stream.
0:14:49 > 0:14:52Which means that, almost certainly, there's fish around.
0:14:52 > 0:14:56But it seems that for the bears, fun is more important than fishing.
0:15:00 > 0:15:03Then, abruptly, one bear's attitude changes.
0:15:03 > 0:15:05This youngster is into hunting mode.
0:15:12 > 0:15:15And it doesn't take long before it catches its first salmon.
0:15:15 > 0:15:19Whoa. That was just too easy.
0:15:23 > 0:15:25Success. Yeah, success.
0:15:27 > 0:15:31The bears continue to catch salmon over and over again
0:15:31 > 0:15:33and this is quite a feat.
0:15:33 > 0:15:37Salmon are predators themselves - they're snappy, slippery and quick.
0:15:37 > 0:15:40Right now, it's just about piling on the pounds.
0:15:40 > 0:15:44Over these few months they could put on my bodyweight in fat,
0:15:44 > 0:15:46just purely from munching down on salmon...
0:15:47 > 0:15:49..and he's despatching it right now.
0:15:51 > 0:15:55And all that fatty salmon attracts bears in their droves.
0:15:56 > 0:16:01We have new arrivals in every sense of the word.
0:16:01 > 0:16:05A mother's just arrived with two very small cubs
0:16:05 > 0:16:08and these are this year's cubs.
0:16:08 > 0:16:11They're just little teddy bears, bundles of fluff
0:16:11 > 0:16:13and she now has three mouths to feed,
0:16:13 > 0:16:16so she's going to have to get busy fishing.
0:16:16 > 0:16:19A mother bear has much to fear from other bears.
0:16:19 > 0:16:22An adult male will not hesitate to kill her young cubs.
0:16:22 > 0:16:25With the two over-excited bears already fishing,
0:16:25 > 0:16:27she needs to act fast.
0:16:28 > 0:16:32Luckily, they're more interested in the salmon than in her cubs.
0:16:34 > 0:16:37There are very few cuter animals in the whole natural world
0:16:37 > 0:16:39than a bear cub.
0:16:39 > 0:16:42It really is quite something to see what they turn into.
0:16:42 > 0:16:44I mean, this little animal you just really want to go over
0:16:44 > 0:16:48and give a great big hug is going to turn into one of the most
0:16:48 > 0:16:51awe-inspiring carnivores on Earth.
0:16:51 > 0:16:55The mother's experience and skill is obvious.
0:16:55 > 0:16:57Oh, Mum's off, Mum's running.
0:16:58 > 0:17:01It's a flurry of feet, claws and teeth.
0:17:04 > 0:17:06And she's under, her muzzle beneath...
0:17:06 > 0:17:08Yes, look at that!
0:17:10 > 0:17:13That's an enormous salmon,
0:17:13 > 0:17:14an enormous amount of meat on it.
0:17:16 > 0:17:19She's coming closer and closer to us with it.
0:17:20 > 0:17:23I think probably the reason that she's run with it like this,
0:17:23 > 0:17:26is so that she can take it away from the two other younger bears.
0:17:26 > 0:17:28She wants to make sure that her and her cubs
0:17:28 > 0:17:30can enjoy the meal in peace.
0:17:31 > 0:17:33It's been a rare bear day.
0:17:33 > 0:17:37Fighting, splashing, playing, hunting.
0:17:37 > 0:17:39The grizzly bear in all its glory.
0:17:46 > 0:17:48The largest land carnivore.
0:17:50 > 0:17:52Could out-sprint an Olympic athlete.
0:17:53 > 0:17:56Long, curved claws to snag slippery salmon.
0:17:58 > 0:18:00Nothing like as cuddly as they look.
0:18:02 > 0:18:03Deadly.
0:18:04 > 0:18:05For our final mission,
0:18:05 > 0:18:08we're ocean-bound to find another Alaskan giant.
0:18:08 > 0:18:11For the next few days we're going to be out at sea in search
0:18:11 > 0:18:15of one of the largest predators on the planet - the humpback whale.
0:18:19 > 0:18:22Humpbacks are one of the most massive creatures on earth.
0:18:22 > 0:18:25They can get to be over 15 metres in length,
0:18:25 > 0:18:28weigh 40 tonnes, and eat a tonne and a half of small fish,
0:18:28 > 0:18:31crustaceans and plankton in a day.
0:18:32 > 0:18:34They focus on areas where there's most to eat,
0:18:34 > 0:18:37and can move massive distances to find it,
0:18:37 > 0:18:42so we have to follow, bouncing all day long in our little boat.
0:18:42 > 0:18:45The crew are eagle-eyed and ready for action.
0:18:46 > 0:18:47Some of the time.
0:18:51 > 0:18:54We're now miles away from civilisation so we need to find
0:18:54 > 0:18:59somewhere to camp and I'm thinking that this beach here looks perfect.
0:19:00 > 0:19:02Doesn't get much more dramatic than this.
0:19:06 > 0:19:08It's a classic wild campsite,
0:19:08 > 0:19:11but tent spots need to be chosen with care.
0:19:11 > 0:19:13There's lots of things to consider
0:19:13 > 0:19:15when you're making a camp round here.
0:19:15 > 0:19:16The first of which is going to be
0:19:16 > 0:19:18where the water's going to come up to
0:19:18 > 0:19:20when the tide rises and the second is animals.
0:19:22 > 0:19:25These are bear tracks.
0:19:25 > 0:19:27They're not new, they're quite old,
0:19:27 > 0:19:29but bears wandering through here
0:19:29 > 0:19:32is something we'll have to be very, very careful of.
0:19:32 > 0:19:36The last thing anyone wants is to wake up next to a grizzly.
0:19:38 > 0:19:41We make sure all our food that might attract them
0:19:41 > 0:19:42is kept well away from camp.
0:19:44 > 0:19:47Once camp's set, we make the most of the long hours of daylight,
0:19:47 > 0:19:50to head out on an evening whale search.
0:19:54 > 0:19:56We head to Inian Pass,
0:19:56 > 0:19:59which is where our captain's seen the whales recently.
0:19:59 > 0:20:01In order for me to try and get close,
0:20:01 > 0:20:03I'm going to head out in a kayak.
0:20:03 > 0:20:05So first I need to get kitted up.
0:20:09 > 0:20:12We've found ourselves an absolutely perfect spot.
0:20:12 > 0:20:15We're in a channel with the water completely flat calm.
0:20:15 > 0:20:17The opportunity couldn't be better.
0:20:19 > 0:20:23All we need now is for the whales to play ball.
0:20:26 > 0:20:30After a while. I put down my paddle, sit and wait.
0:20:42 > 0:20:44Goodness. Whoa!
0:20:46 > 0:20:50And in no time at all I am surrounded,
0:20:50 > 0:20:54with whales everywhere, spouting from their blowholes.
0:20:54 > 0:20:57The water looks like it's alive with cannons firing.
0:21:01 > 0:21:05Oh, my goodness.
0:21:05 > 0:21:07But there's an unexpected, uninvited guest -
0:21:07 > 0:21:09Steller sea lions.
0:21:09 > 0:21:11There are hundreds of them, in a mood for mischief.
0:21:13 > 0:21:15This is out of this world.
0:21:15 > 0:21:19The sea lions seem to see the whales as a big plaything
0:21:19 > 0:21:21and they're showing off to us too.
0:21:25 > 0:21:27They're so playful.
0:21:27 > 0:21:31And these animals are here for the same reasons as the whales are -
0:21:31 > 0:21:32food.
0:21:32 > 0:21:36There's an abundance of fish here, primarily herring,
0:21:36 > 0:21:41but also the salmon that are waiting to head up-river to spawn
0:21:41 > 0:21:45and these Steller sea lions have got food in abundance.
0:21:45 > 0:21:47So much food that they can just afford to spend
0:21:47 > 0:21:50an enormous amount of time mucking about.
0:21:52 > 0:21:55With the constant irritation of sea lions leaping all over them...
0:21:55 > 0:21:56Uh!
0:21:56 > 0:21:59..the whales are showing no signs of hunting.
0:21:59 > 0:22:02All they seem to want to do is rest, and talking of which...
0:22:07 > 0:22:10Oh, I am a bit on the chilly side.
0:22:10 > 0:22:13We didn't get to see them actually feeding today
0:22:13 > 0:22:16but got very, very close to those extraordinary animals.
0:22:16 > 0:22:18Hopefully tomorrow, we'll have a bit more luck.
0:22:32 > 0:22:35With the sun up, after a quick wash in the icy Alaskan water,
0:22:35 > 0:22:38and a perfect camp breakfast,
0:22:38 > 0:22:40it's back on the boat for what I hope
0:22:40 > 0:22:43will be another fantastic day for whales.
0:22:45 > 0:22:49We head back to the channel, in the hope to see them hunting.
0:22:49 > 0:22:51And the signs are looking good.
0:22:54 > 0:22:55This looks like the perfect scenario.
0:22:55 > 0:22:58Exactly what we've been hoping to see.
0:22:58 > 0:23:00We've got a group of whales ahead of us,
0:23:00 > 0:23:02I'm not sure how many,
0:23:02 > 0:23:04there could be eight of nine animals
0:23:04 > 0:23:07and they're all very close together.
0:23:07 > 0:23:09And it looks like something's going on at the surface.
0:23:09 > 0:23:12All the animals are going down at the same time
0:23:12 > 0:23:15and that can be a very, very good sign.
0:23:15 > 0:23:17I get back in the kayak to investigate.
0:23:23 > 0:23:24But the whales dive.
0:23:28 > 0:23:30It's a crazy feeling.
0:23:30 > 0:23:33I know that there are at least ten animals...
0:23:34 > 0:23:37..each of which could weigh 30 or even 40 tonnes
0:23:37 > 0:23:40and they're beneath me right now and yet they totally disappear.
0:23:40 > 0:23:44The second they go beneath the surface, they're invisible.
0:23:44 > 0:23:48Then, suddenly, one surfaces right by my kayak.
0:23:48 > 0:23:49Whoa!
0:23:49 > 0:23:52This one's getting a little bit close for comfort.
0:23:52 > 0:23:55Might just move away a bit.
0:23:55 > 0:23:56Look at the size of that tail.
0:23:58 > 0:24:02The flukes must be as broad across as my kayak is long.
0:24:04 > 0:24:06Oh!
0:24:11 > 0:24:13That frightened the life out of me.
0:24:15 > 0:24:18The sound just goes right through you.
0:24:18 > 0:24:22The driving all of that air out of those enormous lungs.
0:24:22 > 0:24:24I mean, these are vast, vast creatures,
0:24:24 > 0:24:28but all you see is that black hump as it breaks the surface.
0:24:30 > 0:24:35But it seems the pesky sea lions are still putting them off their game.
0:24:35 > 0:24:37It's time for a new plan.
0:24:39 > 0:24:40Back on the boat,
0:24:40 > 0:24:43we decide to try our luck further out in the open ocean.
0:24:44 > 0:24:47And on the way, something quite extraordinary happens.
0:24:51 > 0:24:54Oh, look at that!
0:24:54 > 0:24:55Whoa!
0:24:58 > 0:25:02I don't quite believe what I've just seen.
0:25:02 > 0:25:07That is an animal that weighs probably more than a fire truck
0:25:07 > 0:25:09and it's just propelled itself out of the water,
0:25:09 > 0:25:11mere metres from the side of our boat.
0:25:11 > 0:25:17The shower that came off it as it hit the water was phenomenal.
0:25:17 > 0:25:19This whale is definitely in a playful mood.
0:25:23 > 0:25:25Breach after phenomenal breach.
0:25:25 > 0:25:28This whale just doesn't want to stop.
0:25:33 > 0:25:36Scientists are still unsure as to why whales breach.
0:25:36 > 0:25:39It could be to get parasites off the skin,
0:25:39 > 0:25:40to communicate with each other
0:25:40 > 0:25:43or to get a better look around at what's going on.
0:25:45 > 0:25:49But it kind of seems like this whale is just having fun.
0:25:52 > 0:25:55It's only when you're this close,
0:25:55 > 0:25:59that you get any real sense of the size and scale of humpback whales.
0:25:59 > 0:26:02Most of the time all you see is that distinctive hump shape
0:26:02 > 0:26:04as they just come out of the water breathing,
0:26:04 > 0:26:07but when they breach, you can see the whole thing
0:26:07 > 0:26:10and it is simply enormous.
0:26:10 > 0:26:13And this whale is putting on an acrobatic performance
0:26:13 > 0:26:14we will never forget.
0:26:23 > 0:26:25Breathtaking.
0:26:25 > 0:26:27Absolutely breathtaking.
0:26:28 > 0:26:33Despite its size, with just a couple of sweeps of that mighty tail,
0:26:33 > 0:26:35it can propel itself clear of the water.
0:26:41 > 0:26:45I've never had a breach that close to me before.
0:26:47 > 0:26:50Extraordinary, absolutely extraordinary.
0:26:50 > 0:26:52The vast, intelligent, fish munching,
0:26:52 > 0:26:57acrobatic whale is one of the great sights of nature.
0:26:57 > 0:26:59They're also deadly.
0:27:07 > 0:27:09Weighing more than a fire truck...
0:27:11 > 0:27:15..their huge gaping mouths can guzzle tonnes of fish in a day
0:27:15 > 0:27:19and they have the force to launch their whole bodies out of the water.
0:27:21 > 0:27:24These ocean giants are...
0:27:24 > 0:27:26Deadly.
0:27:27 > 0:27:30Join me next time for more Deadly Pole To Pole.