Hydration and Dive Safety

While you were taking your open water or other course(s), I'm sure the importance of hydration while diving was mentioned. But how much was it stressed? Everyone knows that being dehydrated is bad in general, but was the significance of hydration during scuba diving explained to you? Do you know why it's important to scuba diving specifically? Do you know how scuba diving itself dehydrates you faster than many other activities? Do you know the symptoms and what to do about it? If you do, great! If you're still unsure, then this article is for you.

How Does Dehydration Affect Scuba Diving?

To put it simply, dehydration predisposes divers to decompression sickness. (DCS) When the body is dehydrated, the blood thickens. The slower, thicker fluid makes it hard to transport necessary nutrients and exchange gasses. This diminished capacity for gas exchange is what directly affects scuba divers and increases risks for DCS. If the thickened blood can't adequately exchange gasses, then it can't adequately off-gas nitrogen. So even when diving within the limits of the tables or a computer, the dehydrated diver is at a greater risk. This isn't the only issue for scuba divers, though. Dehydration causes other physical side effects that can directly contribute to diver safety: muscle cramping and fatigue, increased heart rate and blood pressure, and confusion. None of those things are helpful to divers and all of them can lead to exhaustion, reduced air consumption, and poor decision making.

How Does Dehydration Happen?

Most of us know how dehydration happens at a basic level: You lose more water than you put in and you end up dehydrated. Simple, right? People think about hydration when they're heavily exerting themselves and sweating profusely. But those things don't happen all that often while scuba diving, so what makes divers dehydrate quicker than normal? How does it sneak up on you? Let's understand that hydration doesn't have to do with just water. Hydration involves a balance of water and electrolytes and it's surprisingly easy to throw off that balance. Let's look at some of the ways that are specific to scuba diving.

Sweating

That sweating contributes to dehydration is no surprise. But people don't often realize how much they're actually sweating inside their wetsuits. Even if you're not roasting, if you're sweating at all outside the suit, you're sweating all over underneath it. Why? Because the suit doesn't allow for the body to cool by air evaporation, so it just keeps trying and trying. The longer you have that suit on out of the water, the more water and electrolytes you're losing due to sweat and you may not even realize it. Try to keep the suit off until right before you're getting ready to dive.

Breathing

Yes, breathing dehydrates you. It especially dehydrates us as scuba divers. On land, we naturally lose some water during exhalation. Go breathe on a piece of glass if you're not sure what I mean. That condensation you see is water coming from your body. So if that happens to everyone, why is scuba diving special? Many people don't realize it, but one of the big jobs the lungs have is to humidify and warm up the air we breathe. The drier that air is, the more our lungs have to work to humidify it and as we all know, compressed air is extremely dry. On top of that, the colder the diving conditions are the more the lungs have to work to warm that same dry air, nearly doubling the effort and moisture loss. So every single breath we take from a compressed air tank, we lose water from our bodies, so much so that nearly a cup can be lost on a 30 minute dive just by the absolutely necessary task of breathing. Score one for the rebreathers on this issue because their air is warmer and more moist.

Sunburn

If you're like most people, you're diving somewhere warm and sunny. And if you're like most people, you don't get enough sun normally so you're probably getting sunburned on your dive vacation. Fluid loss occurs when the skin is burned and the body immediately sends fluid to the skin. The warm sun then evaporates that moisture and fluid is completely lost. Wear sunscreen and keep covered!

Wind/Evaporation

Another issue with scuba diving out on a boat in the middle of the ocean is wind. Generally riding in a boat involves wind of some sort, as does the ocean in general. Sweat and other moisture is evaporated by this wind and increases dehydration Salt Chances are the diving you're doing is in saltwater. The boat ride out to the dive site mists salt onto your skin, then you jump into the salty water, and afterwards you sit around with the dried saltwater on your skin. This water evaporates (thanks to the sun and wind) leaving behind salt crystals that leech the moisture directly out of our skin. Try to rinse off if fresh water is available.

Immersion Diuresis, aka Peeing in Your Wetsuit

Have you noticed that when you're diving you tend to pee a lot? This may erroneously lead you to believe that you're well hydrated when that may not actually be the case. When we jump into cooler water, blood is shunted from our limbs to our core in an effort to keep warm. In response to the inevitable increase in blood pressure, the body then starts flushing fluids. In addition to the cold, the water pressure also increases blood pressure, doubling the effect of the cold water. Both of these things directly affect scuba divers and result in divers urinating much more often than they should and losing fluids and salt. Obviously, this is a contributor to dehydration.

Vomiting

Whether it's from sea-sickness or partying, vomiting will severely dehydrate you from direct fluid and electrolyte loss. Try to manage sea-sickness if you can, and continue to try and drink water or sports drinks in between bouts. And even though you may be on vacation, if you're scuba diving try to minimize your drinking at the very least enough to keep yourself from praying to the porcelain god nightly.

Alcohol

Yes, you're on vacation. But if it's a dive vacation, drinking should be minimized. I'm not saying you can't have a couple cocktails once you're done diving for day, but too much alcohol is a very bad thing when diving. For one thing, alcohol is a diuretic which means it's going to make you pee more and we've already established that can be a bad thing. It also has a lot of sugar in it and when you drink things high in sugar, the body has to dilute them with water.

A good rule is for every drink you have, drink a glass of water. What I generally do is have an alcoholic drink, then a glass of water, then alcohol, so on and so forth. What this means is I don't get hungover and I don't get dehydrated because of the alcohol. Just an idea!

Symptoms of Dehydration

Now we've gone over the various ways divers get dehydrated, so how do you know if you are dehydrated? Some symptoms are very obvious, others maybe not so much.

Thirst (this is generally the first symptom)
Headache
Dark urine (ideally urine should be nearly clear - unless you're on certain medication, have specific medical conditions, or have eaten beets)
Sleepiness
Lightheadedness
Dizziness
Confusion
What Do You Do?

Well first off, what you do NOT do is drink gallons of water before or during your dive vacation. Too much water can have just as many hazards as too little. The key is just to remain habitually hydrated by drinking normal amounts of water at regular intervals prior to and during your vacation. And yes, water is your best choice.

Some sports drinks are good too, but remember they do have high sugar content which can counter some of the hydration you get. The bonus with sports drinks is that they help with replenishing electrolytes. But don't drink them in place of water, drink them in addition to water. Energy drinks contain a lot of sugar and caffeine, both of which are going to act against your hydration efforts, so best to stay away from them. Water, water, water.

Eating helps with hydration too. If the boat you're on offers you fruit wedges during the day, eat them because they contain water, vitamins and fructose. Some salty snacks will replenish electrolytes too.

Basically, if you do anything that causes fluid loss then you need to replace those fluids. If you get sunburned, you need to drink more water. If you're drinking a lot of alcohol, you need to drink more water. If you're vomiting, you need to drink more water. Get the idea?

Hopefully now you understand the reason that divers need to stay hydrated, how fluid loss occurs for divers, and how to fix it. We all want to have safe and healthy dive trips and vacations and proper hydration is part of that. Incorporate it into your next dive plan!

Shelley Collett ~ Freelance Writer ~ PADI Scuba Instructor

Kathy Dowsett
www.kirkscubagear.com

11 Quick Tips for Avoiding Motion Sickness

How Motion Sickness Occurs

Our body’s primary motion-sensors include the inner-ear sensors, our eyes and deeper tissues of the body surface. Technically speaking, the inner-ear sensors detect changes in acceleration rather than motion, such as the movement a boat makes when bobbing on top of waves in the ocean. When our body’s internal instruments sense these acceleration changes, and those changes aren’t confirmed by other sensory inputs, such as visual feedback from our eyes, the conflict in the sets of data they deliver to the brain can trigger motion sickness. Scientists aren’t sure what causes the nausea that comes with motion sickness, but the most popular hypothesis is that the conflicting data from multiple sensors causes the brain to assume that toxins have been ingested, and the body’s automatic response is to internally induce vomiting.

Even the smallest things can disrupt comfort while traveling and diving. Perhaps nothing ruins a dive trip more quickly than an urgent need to “feed the fish” from the railing. Thus, most divers try very diligently to avoid getting motion sickness – but how? What really works?

First, we need to understand what causes motion sickness. Often termed “sea sickness,” this malady really has little to do specifically with the ocean and everything to do with motion, so “motion sickness” is a more universally accurate term. When such motion causes the tiny sensors in our body to register something’s amiss, we start to feel a bit queasy, and if not remediated quickly, nauseous.

So how can we avoid motion sickness? Here’s an 11-part strategy:

1. Need to feed. A meal before you board is highly important. For most people, an empty stomach is more sensitive to being irritated, so filling it with comfort food 45-60 minutes before leaving shore is smart. Load up on carbohydrates at breakfast and avoid acidic and greasy foods, as they may contribute to motion sickness. Lastly, avoid alcohol and cigarettes.

2. Medicate. If you know you’re especially prone to motion sickness, investigate the use of over-the-counter antiemetic medications such as meclozine (Bonine, Antivert, Meni-D, Antrizine) or Dramamine. Meclozine reduces the activity of the portion of the brain that controls nausea. These medications are highly effective in most individuals, and thus can be a preventive measure for short trips or for mild cases of motion sickness. Be sure to start medicating the night before the dive trip to start establishing the proper blood level of the drug.

3. Go gingerly. In addition to medications, many divers swear that the intake of ginger is a simple and tasty way to help avoid getting ill. If this works for you, it’s an easy solution – just carry a Ziploc baggie of ginger snaps aboard and munch on them before and between dives. Although it’s not yet clear to researchers exactly how and why it works, studies show that the ginger root contains a number of chemicals that seem to help relax the intestinal track. As a result, ginger is often helpful in reducing the risk of nausea.

4. Avoid “conflicting instrument readings.” Look out across the horizon so your eyes can register the same type of acceleration changes your ears are reporting. Avoid visually focusing on things that are close-by, and most especially, avoid reading for more than a few seconds at a time. Also, face the direction the boat is traveling.

5. Your nose knows. Odors can complicate the mix of signals to the brain, increasing your likelihood of becoming ill. Avoid smelling diesel fumes, cigarette smoke, perfume and of course, anyone else’s vomit.

6. Minimize movement. Standing in different locations on the boat’s deck will result in different amounts of velocity/acceleration being transferred to your body. Stay topside, close to the center of the vessel.

7. Keep hydrated. Continue to drink plenty of fluids while on board and throughout each surface interval. This will help keep your stomach more full and will help your body metabolize food and process everything else better.

8. Stay cool. If you become overheated while on deck, you’ll be more at risk of becoming ill. Wear a cap to keep the sun off your head and face, sit in a shady location between dives and peel off part or all of your wetsuit.

9. Heads up! If you feel the urge to vomit, move to the leeward rail (with the wind at your back), lean forward and try to direct your explosion toward the sea. The fish will thank you. Never go into the head (marine toilet).

10. Dive in. If you do begin to feel the early signs of motion sickness, get into the water and submerge several feet below the surface, doing so will usually quell the queasy feelings because your body will stop receiving the conflicting acceleration readings.

11. Regulate it. If you happen to become ill while underwater, such as just after submerging, it’s usually perfectly OK to vomit in your regulator. It’s not the most enjoyable experience, but it’s typically over very quickly and you’ll feel better almost immediately.

The bottom line is that motion sickness can be managed and/or minimized by planning ahead with sufficient sleep, proper food intake, use of medications and consciously taking avoidance actions while on-board, before the first signs of motion sickness manifest.

Kathy Dowsett
www.kirkscubagear.com

Thanks to Scuba Diving

Making the Most of Your Day on a Dive Boat

Arrive at the boat well before departure time. If the crew says it’s okay to board, climb on and take advantage of your punctuality for an unhurried look around. Check out the boat’s layout, find a good spot for your gear that’s out of the way or close to the gate or that offers protection from the sun.

- If you don’t need it, leave it in your dive locker. On a busy dive boat there’s not much space allotted for each diver, so bring only what you’re going to need for the morning or afternoon dives. That way you can stow all your gear at your dive station without it overflowing into your neighbor’s space. If you can’t carry everything in one trip, you’ve probably got too much.

- As soon as possible, assemble you reg and BC on your tank and give them a quick test to make sure the tank is full and all systems are go. That way, if you got a short fill or if a gear failure occurs you still have a hope of getting a replacement. Also, do a final inventory check to make sure you have everything you need for your dives, like both fins, your mask, maybe a trusty pocket light for checking out the holes in the reefs, and, if the boat requires it, a safety signal tube.

- Don’t be shy about asking questions. All dive boats have their own rules and routines, so if you’re unsure about how to secure your tank, where to stow your weights, or which bucket is for mask rinsing and which is for cameras, simply ask. A good crew will always choose answering easy questions up front over scrambling to catch a tank that’s about to topple over or tripping on an errant dive bag. Knowing the proper boat procedures makes life easier for everybody.

- When you arrive at the dive site, resist the temptation to start obsessing on your gear and instead pay close attention to the pre-dive briefing. This is when you’ll learn about bottom contours, prevailing currents, depths and compass directions. Having this info tucked in your head before the dive will make all the difference in your comfort level and confidence during the dive, plus it can avoid having to be retrieved by the dive guide when you get lost, which is always embarrassing.

- Don’t forget to bring some cash for tips. A top-notch boat crew and dive guide who have both skills and sunny attitudes are instrumental in delivering to you a really enjoyable day in the water. Show your appreciation; they’ve definitely earned it.

From Sport Diver

Kathy Dowsett

www.kirkscubagear.com