Women Underwater

A comprehensive resource for women divers.


JILL HEINERTH – A pioneering underwater explorer, Jill Heinerth has dived deeper into caves than any woman in history. Selected for the inaugural class of the Women Divers Hall of Fame, her recent awards include the Wyland Icon and Scuba Diving Magazine’s Sea Hero of the Year. Recognizing a lifetime of contributions to advancing underwater exploration, in 2013, Jill was presented with the Sir Christopher Ondaatje Medal for Exploration by the Royal Canadian Geographic Society. The author of several books about diving Jill currently has two titles on Amazon.com’s extreme sports “Top 100” bestseller charts. She is an active filmmaker, author, a regular Diver Magazine columnist and a highly regarded technical diving instructor. Her company, Heinerth Productions, Inc. specializes in independent publishing, new media content creation, and underwater videography. Jill Heinerth’s professional credentials includes PADI CCR Trimix Instructor Trainer in addition to teaching for several rebreather and cave diving agencies.


RENEE POWER – Since 1994 Renee Power has participated in dozens of underwater research projects and public education outreach efforts with the Cambrian Foundation. With the Foundation dive team, she has explored and surveyed thousands of feet of new passages in Mexico and Florida caves. She served as Expedition Dive Safety Officer for projects in Bermuda and Florida, designing detailed safety and evacuation protocols specific to those regions. Renee is an active PADI Master Instructor. Her technical training certifications include Full Cave, Trimix and the Prism Topaz Closed Circuit Rebreather. Renee is a Disabled Diver International Instructor and has served in the Deptherapy Program with wounded military veterans. Her favorite students are the ones she helps empower to overcome their greatest challenges, obstacles and fears.


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Greenland’s Ice Cap

The Greenland ice cap has an estigreenlndmated volume of 1.7 million km3 with numerous glaciers that extend from the ice cap out to the Davis Strait. The most well-known of these is the Ilulissat Glacier. It is one of the fastest and most active glaciers in the world, creating dramatic and breath-taking scenery of ice and sea. Producing 10% of all Greenland’s ice fields, this glacier represents roughly 35 billion tons of ice a year. The ice fields of Greenland’s glaciers are products of the ice cap, formed form fresh water which has fallen as snow over the past 100,000 years.

Ilulissat is a vibrant town with a popular boardwalk that leads out to the ice field, where people can watch city-block-sized icebergs creak, growl and calf into the sea.


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Changing Salinity in Arctic Waters

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Immense ‘dome’ of fresh water bulging atop Arctic Ocean off Alaska

Doug O’Harra

CPOM scientists have discovered that the freshwater stored in the western Arctic Ocean has increased by 8000 km3 between the mid 1990s and 2010. Credit: UCL – ESA – PVL

Enough extra fresh water to just about fill lakes Michigan and Huron to the brim has collected in the top layers of the Arctic Ocean northeast of Alaska during the past decade, according to new research published in the journal Nature Geoscience.

Driven largely by strong winds and an immense circular current, some 8,000 cubic kilometers of fresh water have bulged up into a widespread dome since the 1990s.

“In the western Arctic, the Beaufort Gyre is driven by a permanent … wind circulation. It drives the water, forcing it to pile up in the centre of gyre, and this domes the sea surface,” lead author Katharine Giles with the Centre for Polar Observation in London, told BBC news in this detailed and graphically illustrated story.

Giles and her four-member team monitored changes in the height of the sea surface between the mid 1990s and 2010 using the Eurorpean Space Agency satellites EFS-2 and Envisat. They found that the overall level in the Beaufort Sea and Canadian Basin has been rising about 2 centimeters per year, mostly during the 2000s.

 “This increase in fresh water corresponds to an increase in the anti-cyclonicity (clockwise in the Northern Hemisphere) of the wind over the western Arctic,” they explained in this story posted by the Polar Observation center.

 “Models had suggested that the action of the wind on the sea surface could cause a raised dome of freshwater to form in the middle of the Beaufort Gyre, but until now there had been no continuous observations of sea-surface height to categorically demonstrate this.”

A reversal of the wind could prompt a release of this fresh water into the rest of the Arctic Ocean or even into the Pacific and Atlantic, the scientists noted.

That’s not all. The scientists also found that the sea surface height didn’t always match the behavior of the wind — leading them to speculate that sea ice tweaks the pattern and changes the freshwater build-up in ways that still need to be analyzed.

“We were surprised to find that our results also suggested that something else was going on,” Giles said here. “One idea is that sea ice forms a barrier between the atmosphere and the ocean. So, as the sea-ice cover changes, the effect of the wind on the ocean might also change.”

There’s actually an ocean of freshwater perpetually sloshing around atop the Arctic Ocean — coming from river runoff, precipitation, evaporation, melting of sea ice and glaciers, and the complex interchange with the Pacific and Atlantic oceans, the authors explained.

“More than 70,000 cubic kilometers of freshwater are stored in the upper layer of the Arctic Ocean, leading to low salinities in upper-layer Arctic sea water, separated by a strong (boundary) from warm, saline water beneath,” the scientists wrote.

How much is that? About 16,800 cubic miles — enough to fill six Lake Superiors.

Where that water flows and how it interacts with sea life and the warmer, saltier water beneath is critical to Arctic oceanography. A different group of researchers reported in Nature a few weeks ago that the central Beaufort Sea was the freshest it’s been in 50 years, with most of the additional water coming from Eurasian river runoff — not ice melt.

“A hemisphere-wide phenomenon — and not just regional forces — has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea,” wrote Sandra Hines of the University of Washington in this story.

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Suunto Provides Computers for Team Sedna

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Diving the D4i Novo Computer

D4i Novo Blue Perspective - Diving Depth MetricI’ve been a Suunto Brand Ambassador for many years and have been using their products for more than two decades. I’ve always been a fan of quality and reliability for documenting my expeditions to extreme environments. Suunto has provided team divers with their flagship D4i Novo computer. This popular design offers lightweight functionality with optional air integration, all in the size of a wrist watch. At the heart of every Suunto dive computer is a mathematical algorithm that keeps track of the diver’s decompression status. The reduced gradient bubble model (RGBM) algorithm was developed by Suunto together with Dr. Bruce Wienke for well over a decade. This adaptable algorithm provides an accurate picture of what’s happening in the body throughout a dive and its reliability has been proven by millions of successful dives.

Suunto dive watches are easily downloadable to PCs and Macs and data can be stored and repurposed using their free DM4 software. With the diver’s permission, this data can also be populated on the movescount.com website and shared through social networks as desired.


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Suunto Gives Direction to Team Sedna

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The Ambit 2S Sport Watch

suunto-ambit2-s-white-hr-l-1Suunto has provided Team Sedna with Ambit 2S GPS fitness watches to track our journey through the Arctic. These advanced devices are used by athletes around the world to track their fitness, journeys and adventures. This particular version of the Ambit is specially designed to fit women’s narrower wrists yet provides full features of the watch. The Ambit has become an open source craze among computer savvy athletes. The data can be repurpose using community shared apps. Clever programmers have created apps such as a cupcake counter, letting a runner know how many cupcakes they have burned off. Other more serious apps help swimmers, triathletes, cyclists plan their training for events and life goals.

Sedna swimmers will gather heart rate data, GPS location, speed and duration in the water. We’ll be using the movescount.com website to log date and shout it out to the world.

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Water Change in the Arctic

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How Climate Change Affects Water in the Arctic

Right now the permafrost is changing fast in the Arctic and will likely shrink more than 10% in the next 20 years with the permafrost borders shifting up to 200 km northward. Where permafrost is present, the ground is frozen up to 500 m deep with only the top meter thawing in summer. That means that lakes, rivers and wetlands in the Arctic do not generally connect with the  groundwater. Surface water is abundant in summer offering breeding grounds for  fish, birds and mammals. That paradigm is changing fast.

When surface water disappears, it affects breeding animal populations and humans who also rely on it for survival.  Therefore, it is imperative that we study the impacts of climate change on general water security in the Arctic.

As the climate warms, natural sources of water and water infrastructure are both affected. Communities and support structure built on permafrost may have to move. Sanitation facilities may also be affected and can contaminate clean water sources if not contained properly.

Water quality is also being impacted adversely as mankind industrializes parts of the Arctic with mining and energy operations. Pollutants are released into the pristine natural environment. Natural pollutants are also released as the permafrost melts. Greenhouse gases are released into the atmosphere by thaw and flooding, when lowlands are swamped from sea level rise and erosion is increased.

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Ice Diving Tips

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Regulators and Cold Water

Walking to the dive site in Russia’s Ural Mountains.

Regulator free-flows are one of the greatest hazards when diving under ice or in very cold water (less than 4°C). The condition is caused by the sudden drop in pressure as air passes from the cylinder through the first stage. When high pressure air passes through the first stage, it hyper-cools the metal moving parts. In a piston reg, small ice crystals can block the piston open, causing more air flow and trapping the piston open, creating a vicious feedback loop of more air, more ice and a runaway free flow. The air pressure overwhelms the downstream valve in the second stage and all of a sudden you are receiving high pressure air right through the entire system, eventually rupturing the LP hose or damaging the second stage. This phenomena can also occur less commonly with diaphragm regulators. To minimize the likelihood of free flow, use equipment conforming to CE standard EN250 (Cold Water Use). Diaphragm regs are generally better than pistons, which allow water to enter the first stage. Diaphragms can also be fitted with cold water kits, reducing the cold water contact with metal, moving parts.

Procedures are critical too. Never inflate a dry suit, inflate your BCD and breathe in simultaneously. To decrease the volume of gas passing through the first stage, do these things independently. Heavy breathing or use of the purge button increases the cooling effect of the airflow, so try to avoid both.

Free flows can also occur at the second stage, usually on the surface and caused by low air temps and breathing a wet reg in the open air. To prevent this, never inhale on a second stage out of the water when you are in a cold environment. To begin your dive, inhale fresh air topside, then dip your head below water and exhale into the second stage. Do this two or three times to warm the second stage and then submerge and begin breathing in a controlled manner.

Ensure that the cylinder and the air within it is as dry as possible. Keep the system warm until the last moment prior to diving.

Between dives, ensure that no water enters the air intake of the first stage when drying the dust cap. If possible, dry the second stage fully before the next use.

Restrict yourself to no-stop dives at depths from which you can make a free ascent in an emergency or carry a redundant tank and regulator, ensuring that you will be able to turn off the valve of the free-flowing tank quickly. Make sure you have practiced using your bailout. Free flows are extremely chilling and you want to switch to bailout as soon as possible.

Ice diving in Tobermory Canada with John Tait and Instructor Dale McKnight. My late 80s retro drysuit might even be coming back in style!

Ice diving in Tobermory Canada with John Tait and Instructor Dale McKnight. My late 80s retro drysuit might even be coming back in style!

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Touch Tanks

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Ruby Banwait our Chief Scientist has brought along mini-aquariums that can be set up at locations along our route. At each community we fill the aquariums with sea water and then go on a collecting dive, bringing back a variety of animals for a short vacation in our tank. The tanks are set up so that one is at eye level for small kids and another is easy to reach into. We show the kids how to gently hold some of the critters and teach them about how they eat and feed. We also share messages about keeping the ocean clean and protecting the habitat for sea life. Ruby is also teaching the team the fun stories we can share to inspire, gross out, and engage the children.

At the end of the activities, we have a release party where the kids help us bag up the animals and return them to the sea. The bits of garbage we collected underwater are disposed of properly and hopefully a seed is planted to prevent future litter.

The experience of working with the kids is moving. They are so enthusiastic about learning and many left us email contact information so we can keep in touch and perhaps pair them with girls in other parts of the world.

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Goodbye Nain, Labrador

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The next stage of our journey begins. We leave Nain, Labrador on the MV Cape Race and head north. The experience here in Nain has been incredible. I think all of us would agree that it exceeded our wildest imaginations. We wanted to tread very lightly and not make any assumptions about storming in with education for the community. Our fears were alleviated immediately. Everyone was eager to learn more about what we were doing. The community gathers around the pier to fish and hang out. They were keen to bring their children to learn about the residents of our fish tanks and talk about scuba, the ocean and the geography of our trip plans ahead. In turn we learned about the Inuktituk names and legends associated with certain marine life. We listened to stories about what was part of the food supply and what was not. We learned about a beautiful way of life that involves a high emphasis on family and community activities. The children are smart, curious and warm and we could not have had a better launch for the Sedna Expedition.

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Outreach Overwhelming

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We had another incredibly rewarding day with the community. We caught a fresh batch of animals from the public wharf. Many people turned up to watch us dive and were prepared to stock up the tanks when we emerged from the water. We also brought home a transom cover that had been lost by a local boater some time ago. He asked us to pick it up for him and was relieved to have his boat part back. I think it had been in the water for a while, because I had to scrape off some resident anemones and other animals before returning it to him.

Ruby got everyone involved in the tanks and we tried to share a delicate message about trash in the ocean as we chatted with the kids. They were very receptive and were eager to touch, hold and learn about the residents on their local pier.

We’ll set sail in the morning from Nain and move north. The ice is socked in around Saglek Inlet in the Torngats so we are not sure what lies ahead.

Thermal Protection Under the Ice

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The Santi Ladies First Suit


lf_drysuitReliable drysuits are critical for survival in cold water. Without proper exposure protection, one could expect to survive for less than 45 minutes in water near freezing. In less than 15 minutes, unconsciousness would be likely.


Santi Diving has outfitted the Sedna team with the first drysuits ever designed specifically for women. These “Ladies First” suits have many special features. The crotch has been recut and reinforcement for better leg motion and comfort. But beyond custom tailoring the suit offers many unique features. It has been redesigned from their unisex line with a right shoulder to left hip zipper. This permits better placement of the left shoulder dump, especially in small women. The zipper is a TIZIP Masterseal design that is flexible and therefore comfortable. The ripstop nylon fabric also allows for stretch and easy movement. As with all Santi suits, they have not cut any of the features made for serious divers. Larger gusseted leg pockets are easy to reach and the right pocket has an extra zipped small pocket for quick access items.


The Santi Ladies First drysuit is produced from lightweight Ripstop nylon fabric especially designed for Santi to achieve the best possible stretch. It is light and soft but at the same time very durable and flexible, which is exactly what any diver needs. The cold water hood is made with supple stretchy neoprene. Recognizing that women’s head to neck ratio is great than a man’s, they added an expansion zipper in the back of the hood. Now it can be easily donned without tearing hair and then zipped for perfect fit.


lf_undersuitOur exposure protection is a full package. Each woman will wear a custom engineered and fitted undersuit made of Thinsulate. The garment also has a net layer, which makes the undersuit even more durable and practically indestructible. The lining is made of soft 190 gram micropolar insulation and the outside layer is constructed of polyamide additionally reinforced with polyester fabric in the most vulnerable areas. A layer of Merino wool next to the skin will add to comfort and warmth.

In between the Merino and the undersuit, swimmers will wear an electrically heated vest which covers the torso and is connected to electrically heated dry gloves. Cinematographers who are likely to experience longer exposure times will wear a heated full undersuit. Dry gloves dock to rings on the wrist to keep the heated gloves from getting wet and a double layer ice hood will keep heads warm. The only exposed flesh will be around the swimmers mouth.


HeatingPackageThe wiring for the heated undergarments is ported through the dry suit inflation valve, which has been replaced with a dual-purpose thermal valve. An E/O connector hanging from the chest plugs into a lithium ion battery pack provided by Halcyon for the project. These specially designed battery packs are intended to provide up to two hours warmth. Electric undergarments demand high-amperage and therefore high capacity lithium batteries are the best choice. The pack will be mounted on the diver’s harness.


The entire package should allow each woman to remain submerged in water that would be categorized as deathly cold. Close to icebergs and floes, we expect temperatures as low as 28°F/ -1.8°C. One tenth of a degree colder and the entire ocean would be solid!


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Women Underwater – The Comprehensive Guide to Women in Scuba Diving, reaches out to women with specific information about their place in diving. With detailed guidance on equipment, medical issues and social factors, this book reaches women with inspiring stories from mentors who have forged a career in unique underwater fields. Authors Jill Heinerth and Renee Power tackle topics for both recreational and technical divers while featuring their vast experience in instruction, consulting and working in a field predominantly governed by men. At times humorous yet also deadly serious, the book answers delicate questions about hygiene, equipment fit and dealing with sexism. Printed in full color and generously illustrated, Women Underwater will be a welcome resource for any woman diver.

Women Underwater will be available Fall 2014!