Blogs
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.
Dive Travel Curaçao is thrilled to announce the launch of the Curaçao Dive Vacation Guide – 2024 DEMA Special Edition, an expertly curated resource that unveils the unparalleled dive experiences and vacation possibilities awaiting you in Curaçao. Produced exclusively for the Diving Equipment & Marketing Association (DEMA) Show 2024, this special edition guide is packed with exclusive insights, travel tips, and limited-time DEMA offers that make it easier than ever to explore Curaçao’s stunning underwater landscapes and vibrant culture.
Explore Curaçao’s Unmatched Diving Opportunities
With over 70 diverse dive sites along its southern coastline, Curaçao is a bucket-list destination for divers of all experience levels. From thriving coral reefs and intricate marine ecosystems to historic shipwrecks, the island offers a variety of underwater experiences that are hard to match. The Curaçao Dive Vacation Guide – 2024 DEMA Special Edition provides detailed recommendations for both shore and boat diving, making it a valuable tool for divers seeking the best entry points, pristine reefs, and hidden treasures along the coastline. Whether you are an avid wreck diver, or a beginner interested in shallow reefs, Curaçao has it all.
Uncover Eco-Friendly Dive Resorts and Top Dive Operators
This DEMA 2024-exclusive Curaçao guide goes beyond diving to feature insider information on Curaçao’s eco-friendly accommodations, dive resorts, and top-rated dive operators committed to sustainable dive tourism. From all-inclusive resorts that support coral reef restoration initiatives to charming boutique hotels near prime dive locations, the guide helps travelers find the ideal stay to match their vacation goals. It also spotlights trusted dive operators on the island who prioritize environmental preservation, offering travelers a way to enjoy the underwater world responsibly.
Immerse Yourself in Curaçao’s Culture, Culinary Delights, and Adventure
Curaçao offers a vibrant Caribbean culture rich in history, music, and culinary fusion. The guide reveals Curaçao’s hidden gems, including culinary hotspots, historical sites, and eco-tourism opportunities that will appeal to both divers and non-divers. Visitors can explore the island’s iconic architecture, savor a diverse range of dishes influenced by Caribbean, European, and South American flavors, and embark on land-based eco-adventures, such as hiking, cave exploration, and visiting national parks.
Exclusive DEMA 2024 Specials and Limited-Time Dive Packages
This special edition guide features limited-time DEMA 2024 offers on dive packages, accommodations, and excursions. Travelers who book through Dive Travel Curaçao, or our Curaçao dive travel partners attending DEMA, will have access to exclusive discounts on custom dive vacation packages, making it easier to plan an affordable, high-quality dive trip that fits your preferences. The Curaçao Dive Vacation Guide – 2024 DEMA Special Edition is designed to simplify your travel planning and help you dive deeper into the incredible experiences that Curaçao has to offer.
It’s Time to Dive Curaçao!
Now is the time to discover why Curaçao is a top dive destination in the Caribbean! Dive Travel Curaçao invites you to experience an unforgettable dive vacation with exclusive DEMA 2024 specials tailored just for you. To secure your spot, download a copy of the Curaçao Dive Vacation Guide – 2024 DEMA Special Edition and contact the Dive Travel Curaçao team to start customizing your Caribbean dive adventure today.
For more information and bookings, please visit Dive Curaçao’s website or contact our reservations team directly.
Blogs
Dive into Adventure at Hideaway Beach Resort & Spa: The Ultimate Diving Destination in the Maldives
Tucked away in the remote northern Haa Alifu Atoll, Hideaway Beach Resort & Spa is a premier destination for anyone seeking an unforgettable underwater experience. With over 30 dive sites to explore, divers of all levels can witness the unique and mesmerising beauty of the underwater world. Whether you’re a seasoned diver or new to the sport, Hideaway offers an exceptional diving adventure that is not to be missed.
Explore the Beauty Beneath the Surface
Hideaway is perfectly situated near some of the most spectacular dive sites in the Maldives. The dive school and team at Hideaway offer a very personalised experience to ensure each diver gets an interactive, immersive experience.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Unique dive spots such as Theefaridhoo Thila (Heaven and Hell) as one of the 50 best dive sites in the whole of the Maldives, known for its beautiful soft coral gardens.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
As the resort is located next to a channel which gives guests surprise visits from eagle rays, manta rays, guitar sharks and more.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
One of the standout features of diving in the Haa Alifu Atoll is the abundance of rare and exotic marine species. The area is known for sightings of whale sharks, manta rays, turtles, and a variety of colorful reef fish. Diving at Hideaway Beach Resort & Spa offers a rare opportunity to encounter these creatures in their natural habitat, creating lifelong memories for guests.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Whether you’re exploring deep coral gardens, dramatic overhangs, or vibrant reef walls, each dive offers something new and exciting. The visibility in the Maldives is exceptional, often exceeding 30 meters, making it ideal for both underwater photography and general exploration.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Diving for All Levels
At Hideaway, we believe that everyone should have the opportunity to experience the thrill of diving. That’s why we cater to divers of all levels, from beginners to experienced professionals. Our professional dive center, led by expert instructors, offers a range of courses and guided dives. If you’re new to diving, you can start with an introductory course that will teach you the basics of scuba diving in a safe and controlled environment.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
For more experienced divers, we offer advanced dive courses and guided excursions to some of the more challenging dive sites. Our instructors are knowledgeable and passionate about the local marine life, ensuring that every dive is not only safe but also informative and enjoyable.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Exclusive Diving Offer
To make your stay even more unforgettable, Hideaway is offering an exclusive diving package designed to enhance your experience both above and below the water. When you book a minimum 7-night stay, you’ll receive:
- 35% discount on room rates.
- Complimentary diving: 3 dives per person for 2 guests, allowing you to experience the beauty of the Maldives underwater world.
- Free meal plan upgrade: enjoy a complimentary upgrade from Bed & Breakfast to Half Board, or from Half Board to Full Board. Guests who prefer the White Platinum Plan (WPP) can avail it at a discounted rate.
This incredible offer provides the perfect opportunity to experience world-class diving while enjoying all the luxury and comfort that Hideaway Beach Resort & Spa is known for.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Combinable Offers for Even More Value
This diving offer can also be combined with our Anniversary and Honeymoon offers, allowing you to create the perfect celebration package. Whether you’re celebrating a milestone or simply seeking a romantic getaway, this offer ensures that you can enjoy the best of both worlds – luxurious accommodations and unforgettable diving adventures.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Terms & Conditions
- This offer is available exclusively for bookings made through the official Hideaway Beach Resort & Spa website using a specific booking code.
- The offer cannot be combined with other promotions available on the website or through other channels, nor can it be redeemed for cash.
- All dives are subject to weather conditions, ensuring the safety and enjoyment of all guests.
- Black-out dates: This offer is not available from 24th December 2024 to 9th January 2025.
To book this exquisite offer, use the Promo Code: SCUBA24FD
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Hideaway is not just a resort; it’s a sanctuary for those seeking peace, adventure, and luxury. With spacious villas, private pools, and world-class dining options, the resort offers everything you need for a perfect holiday. From tennis, golf, gym, cycling to the exquisite underwater activities, unique dining options, Hideaway has something for everyone. And for diving enthusiasts, it provides an unparalleled opportunity to explore some of the most beautiful dive sites in the world.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
Our dive center is fully equipped with state-of-the-art gear, ensuring that every dive is safe, comfortable, and enjoyable. Our instructors are passionate about the underwater world and are eager to share their knowledge with you, whether it’s your first dive or your 100th.
Email: reservations@hideawaybeachmaldives.com / Call: +960 650-1515 / Website: www.hideawaybeachmaldives.com
The Ultimate Dive Adventure Awaits
If you’re looking for an unforgettable diving holiday in the Maldives, look no further than Hideaway Beach Resort & Spa. With over 30 dive sites, unique marine life, and exclusive offers, we provide the ultimate underwater experience. Whether you’re celebrating a special occasion or simply seeking adventure, our diving package offers exceptional value and incredible memories.
Book now through our official website to take advantage of this exclusive offer and prepare for the dive adventure of a lifetime.
Email: reservations@hideawaybeachmaldives.com
Call: +960 650-1515
Website: www.hideawaybeachmaldives.com
-
News1 month agoIconic SS United States to become the World’s Largest Artificial Reef
-
Blogs3 months agoNovoScuba’s Game-Changing Approach for Dive Store Owners: WE PAY YOU!
-
News2 months agoBook Review – 52 Assignments: Underwater Photography
-
Gear News2 months agoDYNAMICNORD – New German diving brand enters the British market
-
News2 months agoExploring Cenote El Pit: A Diver’s Dream
-
Gear News2 months agoTry BARE drysuits (and maybe even win one!) this Friday with Sea & Sea at North West Dive Fest
-
News3 months agoComing Soon – 52 Assignments
-
News3 months agoSave £200 per person per week at Pole Pole Lodge with Dive Worldwide