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Myth – Hydration is the most important factor in avoiding DCS
By Mark Powell
The maintenance of a good state of hydration is generally considered to be very important for overall health and dehydration can have significant implications on health and exercise performance. Dehydration has long been considered by many divers to be one of the most significant, or even THE MOST significant, factor in DCS risk other than following correct dive profiles.
The idea that hydration is the most important factor in avoiding DCS has been repeated so often that it is taken as an undisputed fact. Many diving manuals repeat this misconception and there are countless articles online which make the same point.
As we have already seen in this series, just because something is repeated over and over again, does not mean it is a fact and widely believed rules are sometimes found to be based on no evidence at all.
Historically there has been very little research on this point, as it was taken to be self-evidently true by many, although rejected by others. There were only a very small number of studies investigating the topic although in recent years this gap has been slowly been addressed as researchers have tried to prove or disprove the idea.
If we look at the scientific evidence for the impact of hydration on DCS risk we can find one paper from 2007 which showed that diving causes dehydration [1]. Another showed that prehydration resulted in a reduction in bubbling post dive [2] and a third showed a reduction in DCS risk [3] although there were some queries about this study. None of these were conclusive and the reduction in bubbling and DCS risk was not huge. This seemed to imply that the benefits of hydration have been overstated at best and does not have anywhere near the impact that was believed. This is especially true when compared to the impact of other forms of preconditioning such as vibration or sauna or when compared with other factors such as temperature which provided a much bigger change in DCS risk.
However, some more recent papers seem to show that hydration does indeed have an impact on DCS risk although less than many other factors such as temperature and exercise [4].
At the same time that the benefits of hydration were being questioned, the risks of over overhydration were starting to be considered.
In particular, excessive overhydration (hyperhydration) can increase the risk of immersion pulmonary edema. However, in some circles this has been misinterpreted as meaning that a normal level of hydration is bad as it increases the risk of this condition.
MYTH – Hydration increases the risk of IPO/IPE
Immersion pulmonary odema/edema (IPO/IPE) occurs when fluid leaks into the alveoli in the lungs. This results in sudden shortness of breath, cough and sometimes blood-tinged, frothy sputum.
IPO was once considered rare, but is now more widely recognized. While the actual numbers of cases are unknown, it is most likely underdiagnosed. This might be because:
- It is difficult to detect in fatalities.
- It can be mistaken for drowning.
- Mild cases of IPE can resolve spontaneously.
Factors contributing to IPO may include:
- Hydrostatic pressure gradient
- Cold-induced vasoconstriction
- Exertion
- Hydrostatic gradient between mouth and alveoli
- Inspiratory resistance caused by the regulator
- Increased gas density at depth
- Excessive pre-dive hydration
- Hypertension
Many of these factors may be present in adventurous or technical diving. Divers Alert Network (DAN) recommends that you abort the dive as quickly and safely as possible if you experience:
- Sudden shortness of breath.
- Persistent cough.
Upon surfacing breathe 100 percent oxygen and postpone further diving until you can consult a physician.
Although mild cases of IPO can resolve without further treatment once a diver has exited the water, respiratory distress while diving can be extremely dangerous. IPO becomes an even greater concern when you face an extended decompression obligation. Here you must balance the risks of:
- IPE symptoms worsening if you remain under water.
- Suffering DCS if you shorten or skip decompression stops.
You will notice that in the description above, one of the factors contributing to IPO is listed as “Excessive pre-dive hydration”. As mentioned earlier this has, in some circles, been misinterpreted as meaning that hydration is bad as it increases the risk of IPO.
When considering hydration levels, it is important to remember that there are three relative states. Which in layman’s terms we describe as dehydration, proper hydration and excessive overhydration. I have avoided the more scientific terms hypohydration, euhydration and hyperhydration in order to make this explanation more accessible to the non-scientist.
As proof that this myth exists, I have included below an extract from a genuine email I received from one of my students;
“I genuinely believed (I don’t know where I got this from) that if you drink anything before a dive, you’re putting yourself at risk of getting IPO. I didn’t realise the shear amount you actually had to drink to increase that risk. So on occasion I’ve had a tea between dives and then jumped in for a second dive and in the back of my mind be thinking ‘I hope I don’t start coughing uncontrollably now and give myself IPO because of that tea’”
One of the most commonly referenced articles on IPO, and an article that the student above had definitely read, contains the following quote [6] “I am particularly concerned that many divers overhydrate with fluids before a dive, in the belief that it will protect them against decompression illness. The evidence that it protects is not convincing. In contrast there is unequivocal evidence that excessive hydration increases the risk of IPO in both divers and swimmers. Overhydration has an additive effect on the increase in alveolar capillary pressure resulting from immersion. So I strongly advise divers not to overhydrate before diving.”
As you can see this does not state that an extra cup of tea will cause IPO but you can see how a myth could grow from this. It is easy to take the statement “I strongly advise divers not to overhydrate before diving.” and misremember it as “I strongly advise divers not to hydrate before diving.” This advice does not distinguish or give any advice on where is the line between hydration and overhydration? Is that extra cup of tea enough to tip us over the line into overhydration?
To answer the question about the difference between hydration and excessive hydration it worth looking at the article described as ‘unequivocal evidence’ in [5]. This refers to a study carried out on military swimmers.[6] An extract of the study is shown below; “Thirty young men on a military fitness training programme were engaged in a swimming time trial over 2.4 km in the open sea. The sea was calm and the measured water temperature 23°. They swam in the supine position wearing only a bathing suit and using fins. Because of the high heat load expected, the swimmers had been instructed to drink large quantities of water before the swim, to avoid becoming dehydrated. They each drank about five litres of water during the two hours preceding the exercise.”
Five litres (8.8 pints) is a huge volume of water to drink in a two-hour period. For someone who was already well hydrated it could easily put them into a position of hyperhydration. Although it might not be a problem for someone who started out in a dehydrated state. The key point is that there is a big difference between proper hydration and excessive overhydration (hyperhydration). A large glass of water, a 1 litr bottle of water or even a large mug of tea is not excessive overhydration.
Conclusion – Myth or not?
Hydration does indeed seem to be a factor in DCS risk and it seems clear that being properly hydrated is a good thing for health in general and also for diving. Hydration is not be the most important factor in reducing DCS risk but anything that reduces DCS risk at all is a positive thing. Excessive overhydration can increase the risk of IPO but excessive overhydration is not the same as being properly hydrated.
Being properly hydrates gives some advantages in reducing DCS risk and likely does not create undue IPO risk. As in so many areas of life there is a balance. Do not dive while you are excessively dehydrated and do not dive while you are excessively overhydrated. Stick to the Goldilocks zone – not underhydrated, not over hydrated but just right.
How to hydrate
The other conclusion we can draw from this discussion is that educators, scientists, researchers, speakers and writers need to be careful about the impression we create. An article or conference presentation may contain perfectly truthful information but that can be misinterpreted and be seen as promoting a very different conclusion to the one intended. This is exactly how myths develop.
Thank you to Neal Pollock who reviewed several early drafts of this article to ensure that my attempts to explain these concepts in non-scientific language did not lose any of the scientific validity. Any errors or misunderstandings are still down to me.
References
[1] Williams ST, Prior FG, Bryson P. Hematocrit change in tropical scuba divers. Wilderness Environ Med. 2007;18(1):48-53.
[2] Gempp E, Blatteau JE, Pontier J-M, Balestra C, Louge P. Preventive effect of pre-dive hydration on bubble formation in divers. Br. J. Sports Med. 2009;43:224–228.
[3] Fahlman A, Dromsky DM. Dehydration effects on the risk of severe decompression sickness in a swine model. Aviat Space Environ. Med. 2006;77:102–106.
[4] Wang Q, Guerrero F, Theron M. Pre-hydration strongly reduces decompression sickness occurrence after a simulated dive in the rat. Diving Hyperb Med. 2020;50(3):288-291.
[5] https://www.bsac.com/news-and-blog/the-hidden-killer-immersion-pulmonary-oedema-ipo/
[6] Weiler-Ravell D, Shupak A, Goldenberg I, Halpern P, Shoshani O, Hirschhorn G, et al. Pulmonary oedema and haemoptysis induced by strenuous swimming. BMJ. 1995;311:361.
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EXCLUSIVE: Jeff Goodman interviews Mark Spiers, CEO of New Scuba Diving Training Agency NovoScuba
NovoScuba’s Game-Changing Approach for Dive Store Owners: WE PAY YOU!
The diving world thrives on passion and adventure, but for many dive store owners, the financial and operational challenges can be as deep as the ocean.
NovoScuba, an emerging force in the diving world, is on a mission to transform this landscape for the better. With a revolutionary approach to dive store and training agency partnerships, NovoScuba is setting new standards for how dive stores can thrive while keeping their focus on delivering exceptional diving experiences.
A New Paradigm: NovoScuba’s Bold Mission
NovoScuba’s mission is straightforward yet profound: to disrupt the traditional dynamics between dive store owners and training agencies. Traditionally, dive stores have been subjected to substantial fees charged by training agencies, for membership, materials and certifications. These costs have often placed a heavy financial burden on store owners, cutting into their profits and limiting their ability to offer competitive prices to customers.
NovoScuba flips the script by offering a model where dive stores earn money, instead of paying high fees. Dive stores receive commissions for every student they register, and their certification costs are covered. This new model not only boosts profitability but also ensures clients get top-quality training at unbeatable prices.
Financial Upsides: Earn From Student Registration
NovoScuba’s approach is simple yet revolutionary. Dive stores partnering with NovoScuba can earn commissions for every student they enroll.
Here’s how it works: For every student enrolled through NovoScuba, dive stores receive a commission. Each student enrolled will receive their e-learning materials and certification credit included in their subscription. This arrangement is a significant departure from the traditional model, where dive stores often struggle to manage high overhead costs related to training fees and certification expenses.
NovoScuba’s approach ensures that dive stores can focus on what they do best—providing top-notch diving experiences—without being bogged down by excessive financial burdens, and the need to carry large stocks of materials.
Quality Training at a Great Price
NovoScuba stands out by offering high-quality, ISO certified, training that doesn’t break the bank, in fact our students will pay less than with most competing agencies. Clients benefit from top-notch education and safety standards at competitive prices. Dive store owners can confidently promote NovoScuba’s programs, knowing they’re offering fantastic training at affordable rates. This balance of quality and affordability helps dive stores build a strong reputation and attract more customers.
Your Brand is Your Business: NovoScuba’s Commitment to Showcasing Your Identity
At NovoScuba, we understand that your brand is your most valuable asset, and we’re committed to putting it front and centre. Unlike agencies that charge high fees to promote their own brand, we believe in investing in yours. With NovoScuba, you won’t be paying to advertise someone else’s logo alone, — our focus is on showcasing your unique identity. Certifications prominently feature your brand, as well as the training agency, reinforcing your store’s image and brand every step of the way. We’re here to support and elevate your brand, ensuring that your investment directly benefits your business.
Affordable Membership: An Investment in Your Success
NovoScuba’s membership model is designed with dive store owners in mind. Membership fees are kept low and include annual Pro member fees for your team. Payment can be made monthly or annually in your local currency, avoiding the hassle of exchange rate fluctuations. NovoScuba promises no exchange rate changes without a six-month notice, ensuring financial stability and simplifying budgeting. With a membership lasting 12 months from date of joining, you’ll enjoy a full year of NovoScuba’s benefits and support.
Streamlined Operations: Simplifying Your Workload
Handling administrative tasks can be a challenge, but NovoScuba makes it easier. We’ve streamlined certification procedures and reduced paperwork to help dive stores operate more efficiently. Certification processing is quick and straightforward, allowing more focus on teaching and customer service. Our system minimises bureaucracy by storing necessary forms in student profiles, reducing paperwork and administrative delays.
Crossover Made Easy
For dive stores looking to transition to NovoScuba’s model, the crossover process is designed to be smooth and hassle-free. NovoScuba provides support to ensure that the transition is as seamless as possible, helping dive store owners integrate into the new system with minimal disruption. Experienced dive Pros don’t need to undergo extensive retraining. Our crossover is designed to familiarise Pros with NovoScuba’s user-friendly platform, standards and course structures, and not to waste time and expense re-training in water.
With just a few simple steps, you’ll be ready to offer top-notch training through NovoScuba.
Comprehensive Business Support and Training Included in Your Membership
NovoScuba goes beyond financial benefits by offering experienced support and training. This value added service includes:
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- Ongoing Support: NovoScuba’s commitment to its partners extends beyond initial training and setup. The company offers ongoing support to address any issues or questions that arise. This continuous support ensures that dive store owners have a reliable resource to turn to whenever they need assistance.
Embracing Digital Natives: Instant Evolution and Continuous Improvement
NovoScuba’s digital-native approach is a game-changer. Leveraging cutting-edge technology, we ensure our services evolve and improve swiftly. Dive stores benefit from instant updates, the latest features, enhancements, and effective solutions, keeping them ahead of the curve. This continuous improvement helps dive stores stay competitive and deliver exceptional services. Whether it’s a new course update, additional marketing resources, or improved e-learning functions, NovoScuba’s digital infrastructure ensures that dive stores are always equipped with the most current and effective solutions. This continuous evolution not only helps dive stores stay ahead in a competitive market but also ensures they consistently provide top-quality services to their clients.
Why Is NovoScuba Doing This? – Fair Profit Sharing for Greater Access and Growth
At NovoScuba, we’ve taken a bold step by paying commissions to stores rather than following the traditional model of training agencies charging high fees. Our mission is to make diving accessible to everyone and to foster a growing community of new divers and continued education. By redistributing profits more equitably between stores and training agencies, we aim to create a more supportive and collaborative environment within the industry. We believe this approach not only helps individual stores thrive but also stimulates overall growth and innovation in diving. Our commitment to fair profit sharing reflects our dedication to the long-term health and expansion of the diving community.
Everyone is getting a piece of the pie.
Getting Started: Join the NovoScuba Revolution
Ready to revolutionise your dive store experience? NovoScuba is here to support your journey toward reduced costs, increased profitability, and enhanced operational efficiency. Get in touch with our team to learn how NovoScuba can transform your business.
For more information, email info@novoscuba.com or visit www.novoscuba.academy.
Lumbalumba Resort – Manado is an intimate dive and snorkel retreat nestled in Manado, North Sulawesi, Indonesia—a hidden gem within the world-renowned Coral Triangle, home to the planet’s highest marine biodiversity.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
With only six luxurious chalets (just nine rooms), we provide a cozy, flexible atmosphere where every guest receives the genuine, personal attention they are looking for.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Our philosophy is simple: we can only succeed when you’re truly satisfied. Choosing to stay small allows us to deliver the extra-special, personalized service you seek, making your experience here genuinely unforgettable.
For us, you’re not just another tourist.
For you, we’re not just another dive resort.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Rustique situated in our lush bontanical gardens are 3 different types of accommodation, including a family Chalet.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Enjoy a relaxing dip in our infinity pool, unwind at the bar, and savor mouthwatering dishes from our renowned kitchen—each meal crafted to delight your taste buds in every bite.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Lumbalumba Resort has two different kinds of boat; our inboard powered, custom-made catamaran, Diver III, and Diver IV, our fast outboard-powered dive boat.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Both are very comfortable with lots of space to relax from, to and in between dives.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Experience stunning visibility and vibrant coral reefs teeming with schooling fish. Bunaken is also a haven for marine life, boasting a thriving population of Hawksbill and Green Sea Turtles. It’s not uncommon to encounter 15 to 20 turtles on a single dive or snorkeling trip!
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
But it’s not just about the big sights and wide-angle views. Close to the resort, you’ll find numerous muck and macro dive sites, reminiscent of the famous Lembeh Strait. And let’s not forget the gem of Lumbalumba—the spectacular House Reef, perfect for exploring at your own pace.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Read what what our guests think about us at
Tripadvisor
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
And read what our guests think of us at
SCUBAVERSE
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Beyond diving and snorkeling, there’s is much to explore on land as well!
Discover the Tangkoko Jungle, home to fascinating wildlife like the rare Black Macaque, vibrant Hornbill birds, and the world’s smallest primate, the enchanting Tarsius Monkey.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
Take a day trip to the Minahasa Highlands to witness active volcanoes, soothing hot springs, bustling local markets, intricate handicrafts, and breathtaking landscapes.
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
And for thrill-seekers, we offer exciting options like white-water rafting, perfect for those craving an extra dose of adventure!
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
We hope this newsletter has provided you with a glimpse into what we have to offer. However, it’s just the beginning—there’s so much more waiting for you!
We offer an incredible combination trip with
Black Sand Dive Retreat in Lembeh
We also offer our
Uncover North Sulawsi program with Pulisan Beach Resort
Email: info@lumbalumbaresort.com / Call: +62 (0) 812 430 2974 / Web: www.lumbalumbaresort.com
GETTING HERE
The easiest way to reach Manado is by flying with Singapore Airlines via Singapore. There are four direct flights each week, taking just three hours to get to Manado, with departures on Monday, Wednesday, Friday, and Saturday.
BOOK NOW!
Email: info@lumbalumbaresort.com
Call: +62 (0) 812 430 2974
Web: www.lumbalumbaresort.com
Facebook: www.facebook.com/lumbalumba.resort.manado
Instagram: www.instagram.com/lumbalumba.resort.manado/
Stay safe and healthy and we look forward to meet you in Manado soon!
Best wishes,
Juud, Roel and the whole Lumbalumba Team
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