If you dream of diving unique and undiscovered places – let’s say, under Arctic icebergs – there are very few people in the world who can tell you what it’s like. One of them is Jill Heinerth, one of the first people in the world to dive underneath an iceberg back in 2002. Here’s a few bits of wisdom about the world’s coldest, loneliest places passed on from one of the sport’s most knowledgeable individuals. It’s one of most unique experiences you can have Diving inside an iceberg in Antarctica was one of the most remarkable things I have ever seen underwater. There were no guidebooks to prepare me for those experiences. Nobody had done it before. It’s nothing like cave diving Iceberg diving is actually very different from cave diving. There are odd vertical currents and surging swells created by mixing waters and bouncing masses of ice heaved up and down on waves. Most iceberg diving is done along a face or wall of ice rather then inside a cave-like area. There are significant risks from going inside a crack or crevasse. Icebergs, especially in the north, are dived at the end of their lifespan. They are fragile. They roll, crack and move in a way than crush a diver in an instant. Wanna dive an iceberg? Head to Iceberg Alley The best place to dive icebergs would be to head to Iceberg Alley in Newfoundland, Canada and dive with operator Ocean Quest Adventures in the early summer months of June and July. They have experience guiding groups to safely dive the icebergs and when you get your fill, you can swim with whales, dive WWII shipwrecks and even dive in a flooded mine. This isn’t for dive rookies You’ll need to have proper exposure protection for the cold water and advanced diver training that includes excellent mastery of buoyancy control, comfort with shooting a DSMB, using a compass and drifting for a safety stop in open ocean. You also need to descend quickly without a reference line since the most dangerous place to be is near a face of ice on the surface of the water. And you’re going to need a helmet In case a loose piece of ice strikes your head. I have been swept through an iceberg on a rocketing current, been inside a cave when the doorway disappeared, was pinned to the sea floor by a raging flow of water and watched an entire iceberg explode into a sea of slush. Speaking of risk, it’s cold – really cold Cold water increases the risk for any dive profile. How long you can tolerate the chilling temperature? Cold water can affect your mobility and comfort if you are not well dressed. You also need to consider drysuit flooding and managing thermal profiles to avoid decompression stress and gear-related risks such as regulator free-flow. You also need to get back quick – a long float on the surface while you await a pickup isn’t an option. We’ve all made plenty of mistakes in diving. If you haven’t made mistakes, you likely aren’t diving. I’m not embarrassed to report that I have made my share. The important thing is that you plan conservatively enough to absorb the issues and come home safely. Icebergs scare me. Always. But my careful forays into the deep chill have been incredible experiences. You’ll literally be swimming through history There is no doubt that icebergs are stunning visual environments. You might be shoulder to shoulder with an ice wall formed by 10,000 years of compacted snowfall or be witnessing the fizz of earth’s atmosphere erupting from some ancient timeframe. Scientists certainly have a lot to learn about sea ice and declining ice shelves around the world and in my lifetime, it is predicted that we may have an ice-free Arctic. Is it worth the risk? I’ll leave that to adventurers and scientists to consider on their own. You can come dive icebergs with me I will be making The Journey of the Iceberg next fall. On Sept. 23, 2017 I will be departing on Adventure Canada’s boat to make a trip from Greenland, across the Davis Strait and down the Labrador Coast to Newfoundland. We have space for ten divers to come along on this amazing opportunity to dive in places never visited with SCUBA! Icebergs calve from the coast of Greenland and make this circular journey across the strait. We’ll follow their course and have incredible diving and exploration opportunities along the way.    READ MORE SIGNAL SEEKER – A SHORT STORY ABOUT BO LENANDER'S LIFELONG JOURNEY EXPLORING THE LITJÅGA CAVE  

In this second part of the Arctic cave diving series, we will explore the Litjåga cave in the Nordland region of Norway. A fierce wind blows over the open plateau. White Mountain tops in the horizon fade into the gray sky. There seem to be so many fells that I wonder if they all even have a name. The road carves a deep track into the snow. The wind is doing everything it can to fill in the track, to erase our narrow path from the landscape. This spectacular landscape belongs to the Scandes, a mountain range that originated some 400 million years ago when Greenland crashed into Scandinavia. This violent collision created a huge mountain range, higher than the current Himalayas. Called the Caledonide Mountains (Caledonide being the Latin name for Scotland), the range reached from Scotland to islands of Svalbard. We actually see the remnants of the insides of these huge mountains. Erosion has worn them down, and many ice ages have carved the valleys. Inside these fells are huge deposits of limestone, formed by the calcite-rich sea floor that was pushed up by moving land masses into the mountains. During the process, the limestone turned into layers of marble, creating favorable circumstances for caves to form. Over the years, water has carved its way through the stone, creating water filled tunnels we shall soon be exploring. As the night falls, we descend from the plateau and enter the thick forest of Arctic spruce. The familiar landscape of the Plura valley greets us. Our car slowly makes its way along the icy road, sliding at every tight turn of the narrow road. We cross the Plura River that originates in close-by Kallvatnet, a vast reservoir 564 meters above sea level. We take the road running along the valley. The last house in line is our target. It is Jordbru, the Traelnes family farm. We are staying next to the spectacular Plura cave, but this time, it’s not what we are here for. Our goal is to explore Litjåga, trying to find out the secrets of the unexplored part of the cave. In this region of Rana, just south of the Arctic Circle, there are about 200 known caves. Altogether about 2 000 caves have been listed in the whole of Norway. Most of them are unsuitable for diving, either because they are dry, too small or too remote. Compared to the tunnels of the Plura cave, Litjåga is lower and narrower, but it can still be dived with back-mounted equipment. Norwegian explorations before us have taken the line to the third sump, a total distance of about 1.4 kilometers from the entrance. That is where our lead divers Sami Paakkarinen and Kai Känkänen intend to continue further on. Day 1 The dawn is gray. Fell tops line the horizon. The wind makes its way up the valley; reminding is what it can be like when the weather gets bad. It is often much colder at this time of the year; luckily the temperature is closer to zero degrees Celsius. Although the water temperature is always the same, surface operations are much more demanding in bitter coldness, freezing the diving equipment and cameras. We assemble our gear and make the last adjustments. We shall be spending over ten hours inside the cave. It means that we need to pack food, clothes, and lights in dry tubes. The tubes need to be carefully balanced to be neutrally buoyant. Dragging tubes along the cave floor or ceiling is not an option. Finally, the cars are packed, and we are on our way. Litjåga is along Route 6, a highway from Mo I Rana to Bodø, south of the spectacular Saltfjellet-Svartisen National Park. The highway is like a downhill skating track, as the snow covering it has melted during the previous day and frozen again overnight. Snowmobiles are the means to transport the gear to the Litjåga spring during the wintertime. The snow plays its usual tricks when Sami and Veli are hauling the heavy sled over the white banks. Torsten Traelnes, the owner of the Plura farm, has kindly loaned us his snowmobile. It has been packed onto the back of his old pickup and hauled on-site, ready for action. With the snowmobile, we can transport the gear over the last half a kilometer of waist-deep snow from the highway to the cave entrance. Although the temperature is quite high considering the time of year, the winds up in the fell make the air biting cold. The Litjåga spring water levels are down, so we are met by a tranquil headpool. There is a constant flow of water supplying a serpentine creek. It takes us a couple of hours to lower scooters, cylinders and rebreathers down from the steep snowy banks of the spring. Sami inspects the tanks, rebreathers, dry tubes, scooters and cameras before the dive. We have brought plenty of cameras to document the event. Thomas Broumand is operating a buzzing quadcopter over our heads as we put on our gear. It sounds like a swarm of mosquitos, reminding us of the summertime. It takes a while to get used to the copter and not stare at it all the time. Janne is carrying the underwater camera, and everybody else is equipped with a video light. The Litjåga spring water levels are down, so we are met by a tranquil headpool. The exploration begins here.Our plan is simple. We have three diving days for the project. The first dive is dedicated to taking tanks and dry tubes through sump one and carrying them over the dry section to sump two. Litjåga is a relatively shallow cave, its depth never exceeding 22 meters. This makes things easy for us, as we don’t have to take deep range gasses into the cave. Also, the volume of bailout gas is quite small. Going deep means an exponential growth in the required open-circuit volume, not just in the number of required gas mixes. Veli Elomaa and Jenni Westerlund descend first into the crystal clear waters, disappearing into the stony well leading down and underneath the fell. Janneand Ifollow, making our way through the narrow passage at the beginning of the cave. We are only just barely able to drag ourselves through the restrictions with our JJ rebreathers. The layered stone forms sharp ledges sticking out of the ceiling and floor. As a result, Janne’s suit springs a leak, making him instantly cold. Fortunately, we are only planning to take the equipment to sump one today. Otherwise, we would have to turn around and fix the leak before continuing. We wait for Kai and Sami to follow, to get some good footage of them pressing through the narrow part. Time to go. It will be another 12 hours before we will see the headpool again. After the restrictions, the cave opens a bit. The video lights reveal a colorful cave, formed of various shapes of limestone. The maximum depth of sump one is 22 meters and the length of the sump is close to 500 meters. The low ceiling requires careful scootering, especially while dragging the meter-long dry tubes behind us. The cave soon plays another trick on us. Sami’s scooter catches on some rubble. One of the propeller blades snaps. Luckily this is the set-up dive with plenty of time and a short distance, so we simply carry on without the scooter and bring it back to the surface later for repairs. The first sump contains a few restrictions and eye-catching marble formations. The layered stone forms sharp ledges sticking out of the ceiling and floor. The maximum depth of sump one is 22 meters and the length of the sump is close to 500 meters. The low ceiling requires careful scootering, especially while dragging the meter-long dry tubes behind us.Surfacing in the dry chamber gives us an immediate idea of the coming challenges. The passage is so low that dragging the rebreather through will mean crawling along the bottom, faces in the silty water. We leave the rebreathers waiting and slip the bailout cylinders through the restriction. After some crawling we enter a 250 meter long dry section has been washed clean by the rushing waters, leaving behind a polished floor of marble and intermittent sand banks. Parts of the dry cave require crawling or kneeling down, which make the 40-kilo dry tube less friendly than in the water. The team surfacing in the first air chamber. From here begins the heavy carrying of gear to sump two, with over 250 meters of crawling and wading. Although we are taking only some dry tubes and stages through the dry section, one of the key challenges of Litjåga is apparent. While working in our dry suits, we soon start to sweat. Our thick undergarments are making things worse. When returning to the cold water, I can immediately feel the problem. Diving in four-degree water while being wet is not the most pleasant of feelings. We use heated vests to keep the upper torso warm, but it does not fully compensate the heat loss caused by the wet clothing. We surface after three hours underground. We have taken the heavy stuff in, helping us move quickly and lightly on the push dive. It is time for some rest at the farm. Day 2 The goal of our project is to extend the line laid inside the cave and to do detailed documentation of the cave. For the purpose, we are using the traditional means of measuring the laid line and directions, but also brand new technology. Sami is carrying an underwater tablet containing software for making precise measurements under water. We also have many GoPros and other cameras not just for stills and video, but also for taking footage for photogrammetry. This new technology allows us to render a computer-aided 3D model of the cave based on video footage and a few measurements. All these gadgets don’t always make things easier. We are delayed because the remote location in the Plura valley obstructs the cellular connection required to update the tablet’s measurement software, something that we had forgotten to do beforehand. Kai and Sami discuss the exploration plan at the Litjåga spring. Kai and Sami are the designated push divers. The plan is to dive quickly through sumps one and two with the whole team and carry the equipment to the beginning of sump three. Kai and Sami go first so that they will have enough recovery time before doing the push dive in sump three. We follow a few minutes later. The dive goes smoothly and everything works fine. We soon surface at the other end of the sump. The first task is to crawl through the restriction, face in the water and rebreather on your back, trying to find a big enough space to squeeze through. Everybody’s panting heavily and cursing as their elbows and knees hit the rocks. I try to shield somehow my dry suit made of Kevlar. Getting a hole in the suit at this point would mean that I had to turn back. It takes about an hour to carry the gear over the dry section and get ready for the second leg. In sump two the passage gets narrower. The buoyancy of the dry tubes seems suboptimal, causing silt to stir up from the bottom. The visibility gets low, and we stick to the line closely. After sump one, we enter a 250 meter long dry section has been washed clean by the rushing waters, leaving behind a polished floor of marble and intermittent sand banks. Parts of the dry cave require crawling or kneeling down, which make the 40-kilo dry tube less friendly than in the water.We surface and meet the lead divers in the dry section between sumps two and three as planned. They are already scouting routes for carrying the equipment to sump three. The dry section after sump one was reasonably easy regarding carrying, with plenty of headroom and a relatively flat bottom. Only in the beginning and the end of the dry cave did the ceiling force us to crawl or kneel. This second dry passage is a totally different story. Its steep walls and narrow passages force us to move slowly and carefully along through the 350 meters of the dry cave. There are two routes to choose from. The lower route means either wet feet or sweating in the drysuit. The upper route leads over treacherous leaps, with 3-4 meters to the stony floor. Carrying a single stage feels heavy, and there are many trips to be made before the gear will be ready for the push dive in sump three. The stones look solid, but they are not. Crossing one of the chasms, a layer of rock suddenly comes loose under my grip. Swaying forcefully to my side I hit the wall, watching the big flat stone hit the floor with a thundering crash. Hanging on to the rock I realize that having a broken leg this far inside would not be a good idea. Getting out through all the restrictions would be a dangerous undertaking while seriously injured. Lunch time. Some warm food to warm up the team. Eventually, we have everything carried over to sump three. It is lunch time. Veli has brought a gas burner that we heartily welcome. Hot soup and meals made from dried ingredients feel incredibly good as the moist, cold and work has started taking its physical and mental toll. Soon Sami and Kai are ready for the push dive. Standing on the narrow strip of sand, we help them kit up and wish them good luck as they disappear into the darkness. We have no idea how long we will have to wait. It all depends on how long the diveable cave continues. We return to the campsite. There is nothing to be done but wait. After some 90 minutes, we are heading back to the sump three from the camp site when we hear noises. Kai and Sami are up. It either means that they have not made it very far from the end-of-line, or they have had some problems. As it soon turns out, they have laid new line but had soon run into an impenetrable passage. In the end-of-line, the cave continues along two different routes, both impossible for rebreather divers to pass. The lower passage ends in a narrow passage, accompanied by a shifting gravel slope. Going through it would mean digging oneself headfirst into a pile of gravel at a depth of 70 meters. Being upside down in a shifting wall of sand is not very tempting option. The upper passage is so narrow that there is no way getting through it in back-mounted gear. Kai and Sami had no option but to turn the dive around. They were only able to lay 40 meters of new line, increasing the sump 3 line to a length of just over 200 meters, and to almost 1.5 kilometers in total. In a sense, the dive was a success as it was carried out as far as possible. It was an obvious disappointment that there wasn’t more cave passage to follow. Sami getting his measurement and mapping tools ready. Could the line be continued one day? Maybe with side-mounted gear and some serious tools to deal with the restriction. But as the cave was already getting so much narrower, the chances are that the diveable passage wouldn’t continue very far. Time will tell whether this really will remain the end of the line. In any case, the challenge of continuing is formidable because of the remote location and depth. There is a certain feeling of achievement. The goal has been reached. But painfully enough, we have only made it halfway and still have to make it out. Hours of hard work still await us. When Sami and Kai have rested enough, we start heading back. Kitting up in the fine sand is challenging. Sand seems to find its way everywhere, causing O-rings to leak and suit zippers to rattle disturbingly. The shallow and sandy entrance to the second dry passage means that the water is all silted out downstream, as we have struggled our way out of the water and back in again. This proves to be exactly the case. I drag the dry tube behind me, soon realizing something has gone wrong when re-packing the tube. It is vertical instead of horizontal, making the going slow in the small tunnel. I feel my way through zero visibility, feeling exhausted already. Finally, I reach the shore and climb out of the water. The balance of the dry tube needs to be fixed. As if this wasn’t challenging enough already, I realize that my suit is leaking. Even though the holes are only needle size, as I later find out, there is enough water seeping in to soak me. I’m trying to figure out the best strategy of getting over the dry passage with all the tanks and tubes. At least I don’t have to worry about sweating as I’m totally wet already. Diving out will not be fun. I’ll just have to endure it, that’s all. The first task is to move the rebreathers. Carrying them is otherwise fine, but the last restriction once again means crawling face-down in the water, squeezing between the rocks with the unit in the back. When reaching the other side of the restriction, I am breathing heavily and feeling totally out of energy. We have a brief discussion. The gear could be left behind for the next day, or it could be hauled out immediately. We decide to carry everything immediately, a decision that I soon regret. The work intervals get shorter and shorter. As your strength dwindles, it becomes harder and harder to find a good step in the streaming water, not to mention climbing over the boulders littering the passage. I keep thinking about the next day. If I can carry all this out, I do not have to return. That gives me just enough strength to get the last cylinders from the sump two. I find a dry pair of gloves in the dry tube. I know they won’t help long, but they feel heavenly until I submerge again. I immediately feel the cold water starting to make its way towards my fingers and gradually numbing them until they are almost useless. After we have carried the diving gear through the second dry chamber, Sami and Kai are ready for the push dive. Standing on the narrow strip of sand, we help them kit up and wish them good luck as they disappear into the darkness. It is time to see how far the diveable cave continues.Although there is only a half an hour dive out, it feels like hours. My hands are clumsy. My thinking is slow, and I have to concentrate on every small task. Each time a stage has to be moved it takes a lot longer than usual. I am shivering. Looking at others, it seems I’m not the only one fighting against tiredness. When we get to the final restriction before the chimney-like crack in the stone leading to the surface, we need to organize our gear for the ascent. This usually takes a minute or two, but this time, it seems it takes us fifteen minutes to get through. Everything is happening in slow motion. When we reach the narrow upwards corridor, I shiver from relief. The last obstacle has been cleared, and the cold doesn’t matter anymore. After more than 12 hours inside the cave, we surface into the night among the fells. The stars greet us, slowly blinking above us as if showing the way home. But I don’t waste any time getting out of the water. Walking along the shore, I feel the water filling my boots. Had the dive been an hour longer I would have been in serious trouble. And as if we hadn’t had enough to endure, the snowmobile decides not to care about our attempts to start it. After an hour of tweaking, the old engine bows and kicks into life. At least we have transportation back to the car. Even with all the carrying it takes a full hour before I start to feel warm again. Day 3 The following morning isn’t the most pleasant. My body is still aching from previous day’s efforts. We still need to complete the photogrammetry from the first sump, so I have no choice but to crawl out of bed. Again we assemble and load our rebreathers into the car. The temperature is still close to zero degrees, but this time, a fierce wind is making the air feel much colder. Being tired and worn out, plus having still damp undergarments add to the chill. My body feels cold, and my sleep-derived mind is slower at making decisions. I have to keep telling myself to keep focused. Entering the water, we soon discover a bigger problem. The o-ring of the camera housing isn’t in place, and the camera is flooding. So much for the photogrammetry. This is such a typical example of small mistakes that begin to pile up when you become tired and try to get too many things done at the same time. We dive anyway and take a few stills. After fetching the stages left behind the day before we were ready to call it a day – and a project. My suit is still leaking, and I happily turn around once the pictures are taken. The push dive is over, but there is still hours of carrying, diving and crawling ahead. After some 12 hours inside the cave, we finally surface.Later on, we are sitting in Torsten’s sauna and reflecting on the excitement of the project. In two days, we were able to push to the end of the line and stretch it a bit further. We were moving fast, with the minimum safe amount of equipment. We were able to help the two push divers reach the end of the line. We would not have been as tired had we allowed ourselves a day or two more for the diving. But we wanted to move fast. And I must admit that is all part of the excitement, pushing the limits enough to feel it with every cell in your body. I am so happy that I am lucky enough to have this possibility. To push on with these determined explorers, always ready to expand the limits. Underwater photos and videos: Janne Suhonen, Kai Känkänen and Sami Paakkarinen Story: Antti Apunen Surface photos and videos: Thomas Broumand Divers: Antti Apunen, Veli Elomaa, Kai Känkänen, Sami Paakkarinen, Janne Suhonen and Jenni Westerlund READ MORE SIGNAL SEEKER – A SHORT STORY ABOUT BO LENANDER'S LIFELONG JOURNEY

In 1979, Bo “Bosse” Lenander was hiking in the Bjurälven natural reserve. He was enjoying the northern Swedish landscape with its lush green beauty of the summer, making his way along the river running through the limestone valley. Bosse arrived at the river source. Being a curious individual, he was soon in the water, freediving to the bottom of the pool. There he found a 10-centimeters wide opening, water flowing through it. There was a cave behind. The Swedish word 'dolin' describes a formation where erosion causes the ground to collapse into a water-filled cave. The cave in Bjurälven Valley originates in the lake Bosse dived, Dolinsjön (Dolin lake), and was therefore given the name Dolinsjö cave. For many years, Bosse's discovery stayed as a footnote to the Swedish cave exploration. Attempts were made to enter the cave, but the hard flow denied access during the summer months, hurling water out at tremendous speeds up to 20 knots. Exploring the cave in winter In 2007, a group of Swedish cave divers decided to make an attempt during the low-flow winter season, even that it meant hauling gear through the deep snow and making a hole in the meter-thick ice. On the other hand, the snow would protect the fragile nature reserve from being damaged by the expedition. The idea proved right. After transporting the gear through the snow filled valleys and forests, divers managed to dig their way in and map 50 meters of the underwater passage. The cave kept going. So the divers returned every winter, to add a few meters of line and discover what's behind the next corner. Signal seeker joins Expedition Bjurälven In 2011, the expedition team invited Bosse to join. A glimmering blanket of snow covered the Bjurälven Valley when he arrived on-site. This time, he decided, there would be no freediving for him. But Bosse had another idea. As he was an active radiolocation hobbyist, he had built a device that could detect magnetic pulses from underground. These, he figured, could be used to pinpoint the exact location of the divers and features of the cave. This may all sound like an easy task until you consider that the cave is surrounded by a thick sheet of marble and layer of gravel originating from the ice age, blocking most signals from passing. Bosse's concept proved to be working and is now used by the expedition to record exact locations of the cave formations. 244 hours of diving in a week The cave was re-mapped during the 2016 expedition. A new generation of precision equipment had become available, and a new map of the cave was soon created, including a full 3-D rendering. Suunto EON Steel compasses were the tool of choice for the underwater mapping. Also, fixed points were placed inside the cave and located on the surface using radiolocation and advanced satellite positioning. In April 2016, the Expedition Bjurälven team managed to extend the mapped parts of the cave to well over 2 kilometers. They found a massive collapse after sump five, and another sump after that. Longest exploration dives to the end of the line took 7 hours to complete. Divers spent 244 hours in the cave during the expedition week. Today, 37 years since Bosse's discovery, Dolinsjö cave is one of the longest water-filled caves in Sweden. Bosse is still an active member of the expedition team, regardless of his age of 70. Well, you know what they say about rolling stones.

Passionate diver, photographer and Suunto’s own diving business line manager, Jukka Saarikorpi is hosting the @suuntodive Instagram account for a week, starting today. Make sure to follow to catch his inspiring images! USS Vanderberg, Florida Key West. © Jukka SaarikorpiWhere are you from, Jukka? I come from Finland. I was born in Tampere and now and live here in Helsinki. I work for Suunto as a diving business line manager. Where do you dive regularly? We tend to travel quite a bit for my vacations so most of my dives are in warm water. We also test diving products for Suunto in the Ojamo abandoned limestone mine, about 100 km from Helsinki in Lohja. There, and also in Baltic Sea, I occasionally do cold water diving. I enjoy warm water diving more and photographing marine animals. In Finland, you see a lot of wrecks, but wildlife is very rare to see while diving. © Jukka SaarikorpiWhat inspires you about the underwater world? I have always enjoyed being near the sea. I used to do a lot of competitive sailing, which I still do. Diving became something that I can enjoy in nice locations. It gives me something exciting to do in my free time. Nowadays, it has turned into work as well, but I still love it! How would you describe your photography style? I mostly use a wide-angle lens and like shooting big animals, wrecks and divers. I try to capture the moment underwater when the light conditions are changing. It makes diving more interesting when you have more challenges to get the “perfect” picture. Is there a story you wish to tell with your images? I love to inspire people to start diving and to appreciate the ocean more. The ocean is something I really value and I hope I can encourage other people to appreciate it too. Where to follow your adventures? You can see my underwater photography on my Facebook page, on Instagram and on my photography website. Main image: Moalboal, Philippines. © Jukka Saarikorpi

A dive computer makes freediving safer, more enjoyable and helps to improve performance. Ute Gessman began freediving before the first dive computers were on the market. The AIDA sport officer and competition freediving judge would instead in those days carry a manometer (a mechanical device for measuring pressure) down with her, which was often inaccurate. Since then, dive computers have become a must for every freediver, she says. “For freediving, you need a freediving computer,” she says. “Without one, you have no idea where you are.” Ute Gessman is competition freediving judge and works for AIDA. © Ute Gessman Here’s why a dive computer is essential kit. Safety first A dive computer can tell you how long you’ve been under the water, your depth, and when you must return to the surface. It also helps your buddy at the surface to keep track of how your dive is going. “I can see when he or she left the surface, how long they’ve been under and when he or she should reach the bottom,” says Suunto’s dive business line manager, and freediver Jyri Vehmaskoski. “A dive computer also tells me when I should go down to do the safety dive, about 10 or 15 m, to make sure they’re okay as they come up.” Jyri Saarikorpi is a freediver and spearfisherman. © DeeDee Flores Preparation “A freediving computer helps you prepare on the surface for a dive,” Ute says. You can use the dive computer to time different breathing exercises, to keep track of your warm up dives, and to tell you when you should commence the dive.” Suunto D4i Novo is a lightweight dive computer that has four diving modes, including freediving. Overcoming anxiety “When most people start freediving, they are a little bit afraid to use the free fall to go down the whole way,” says Ute. “Using a dive computer helps them to relax because it tells you how long you should descend before turning back. “Some people want to work by a time, so they put a dive time in, so they know when two minutes, for example, has passed then they need to go back.” © Ute Gessman To manage dive stages Jyri uses his dive computer to manage the difference stages of a dive. “There are four stages when I dive deep: the first stage is obviously on the surface. I make three stronger kicks to get the dive going with momentum and then I start to relax after that. The second stage involves kicking very slowly, focusing on relaxation. Third stage: I do mouth-fill at about 24 to 27 m (an equalization technique). I set an alarm in my dive computer to mark that. The fourth stage: I stop kicking between 30 and 40 m because my lungs are squeezed and I have negative buoyancy so I don’t need to kick. I use a sound on my computer to signal this. Then I just shut my eyes, relax and do the free fall. During free fall my dive computer notifies with sound at certain depths so I know where I am at.”   After the dive A dive computer records each and every dive in a session so once you’re back on land you can inspect the profile of each one. “The profile shows you if you had a good or bad start, if you took too long to go down, when you might have had equalization problems, whether you dived straight, down, or if you had problems,” Ute says. “You can make the profile really big so you can see every second. You can see exactly how you went down and back again. It gives a lot of information for improving performance.” Click to find out more about the Suunto D4i dive computer!

Underwater explorer Megan Cook is taking over the @suuntodive instagram for a week, starting today, August 1, 2016. Join her as she retraces the first US ocean exploration expedition. Who are you and where are you from? My name is Megan Cook and I am an underwater explorer! I work for a deep ocean exploration and education group called Ocean Exploration Trust and am proud to have fed my insatiable ocean curiosity as a reef fish researcher, marine debris mitigator, freediving instructor, science communicator, and Rolex Scholar. I currently live in Newport, Rhode Island but am inviting you, the SuuntoDive family and fans, along on an adventure with me in Washington State’s Salish Sea on the US west coast. I’m joining my friends to #retracethewake of the United States’ first ocean exploring expedition which travelled the world from 1838-1842. In 1841, the six ships of the US Exploring Expedition rowed and sailed their way around Puget Sound, British Columbia’s Salish Sea and the San Juan Islands pioneering the discipline of oceanography and gathering a rich scientific record to the region. The trouble is…they weren’t divers. We know now they were rowing over the top of some of the richest marine habitats and most productive ecosystems on the ocean planet. Come with me as I sail along the path of these 19th-century explorers diving at their study sites and introducing you to the fascinating life they missed underneath the waves. Where do you dive? I dive wherever I have the chance. I was originally certified in southern Idaho- my home state - hundreds of miles from the nearest ocean. I saw seven tires and one fish in that desert reservoir. Since that time I’ve been thrilled to dive in many beautiful pieces of water from Switzerland to South Africa, Australia to Antarctica! What inspires you in the underwater world? I am inspired by the vastness still waiting to be discovered in our oceans! Over 90% of the ocean remains unexplored. We have barely started reading the owner’s manual for the most important life support system on our planet. I love introducing new people to the ways the ocean touches their life, even if they have never touched the waves. I learn something new every time I put my face in the water and that wonder will never cease. Is there a story that you wish to tell with your images? Rather than highlight my greatest shots, I’m bringing followers live on an adventure as it unfolds. Together the crew share three decades of dive experience, but diving from the S/V Whistledown, a 35 foot, Spencer sloop will be a brand new adventure for everyone involved in this project. This trip has helped me remember that for every brand new possibility on a mile of ocean, there is also a rich history. Many of the creatures we’ll meet during this photography trip will be well-known aquatic neighbours, yet the possibility of discovering new views, and fresh perspective is constant. Moving at sailing speed, I’m looking forward to glimpsing views of the inland ocean that astounded the sailors over 170 years ago. Come along with us using #retracethewake or by following me at @missmegancook. #RetraceTheWake will continue for five weeks sailing around Puget Sound and the San Juan Islands. How to follow along. You can follow Megan’s ocean adventures on Facebook, Twitter and Instagram. The sailing expedition runs from late July - late August 2016 and will be posting using #retracethewake.