By Shelley Collett
Everyone hates it, right? It’s why you see so many people holding their noses before they jump into the water. One of the biggest problem skills I’ve seen as an instructor is breathing without a mask underwater. Some people handle it fine, but others have extreme, nearly insurmountable difficulty with it. After a couple of difficult sessions with some student divers, I decided to try to learn how to teach the skill better. I needed a better way to impart knowledge instead of just saying, “Just don’t let the water in!” without really knowing how to tell them not to let the water in. I really didn’t understand why or how I was keeping the water out myself. I just did it! I always have. I was never a nose-holder.
After some research, I thought I’d share here. I realize there are a lot of experienced divers here, but that doesn’t mean that there isn’t anyone who has issues with this. And, I’m sure we also have some newer divers reading who perhaps barely made it through that skill in the hopes that they would never, ever have to do it again. I’m sorry to say to those individuals... you probably will have to deal with it again. Masks flood, they get knocked off. It happens and you should be prepared for it and be confident that you’ll be okay with it.
While I’m sure you’ve noticed people jumping in while holding their noses, have you noticed all the people not doing it? What do they know that you don’t? Some double top secret dolphin technique? Nah,they just know how to control their body to keep the water from entering too far into their nose. There’s no way to prevent water from getting into your nose proper, but you can stop it from ending up down your throat and choking you. (But if you do know a double top secret dolphin technique, please let me know!)
There are a couple of things that help you keep from inhaling water through your nose in the situation we’re talking about: Soft palate control and Epiglottis control. The two things work in tandem, so it can be difficult to distinguish which is which. I’m hoping the exercises below will help with that.
Testing soft palate control
Put on your mask without the strap around your head and suck in through your nose to try to keep the mask on. If your mask fits correctly, this shouldn’t be a problem. (This is how most folks “try on” masks before buying them anyway) While you’ve got the mask ‘stuck’ to your face, start breathing normally through your mouth and keep the mask on your face. Tilt your head down a bit so that you know the mask isn’t just balancing on your face.
If you can do this for a bit, then you have what it takes to breath without a mask on; you have soft palate control. You just need to get over the psychological aspect of breathing with water on your nose.
If the mask immediately drops off of your face, then you don’t have very good soft palate control at all and you should learn and practice it.
Epiglottis and soft palate control
Now a new test. While exhaling through your mouth, cover your mouth with your hand to prevent air from escaping. Did your cheeks puff up? They should have! And, you should not be exhaling through your nose. That’s soft palate control.
While still trying to exhale, move your hand away. If you immediately exhale through your mouth, you used soft palate control. If you paused before exhaling through your mouth, that was your epiglottis. Either is okay, we’re just trying to get you to understand your own body at this point and how things work and feel.
Now we’re going to try alternating a bit. Take a breath, exhale through your mouth, then cover your mouth and switch to exhale through your nose. Did you feel a little nudge or jolt above and at the back of your tongue? That was your soft palate opening to let the air out of your nose.
Maybe you felt a little jolt closer to your lower neck or chest. If so, that’s your epiglottis.
Alternate now between exhaling through your nose and trying to exhale through your covered mouth. Do you feel that control? Remember it. That’s how you keep water out too!
Practice makes perfect if you’re having difficulty with this. I don’t think I can stress enough how important it is as a diver to be comfortable with water on your nose. Comfortable to the point that you’re not going to panic and bolt to the surface, at least. Practice in a tub, pool, hot tub, even the shower. (you could flood your mask in the shower, stand with it flooded and just breathe through your mouth) Practice it a little every time you dive until you are comfortable with it. It will make you a more confident diver and a safer diver.
Nitrox For Beginners
By Jessica Vyvyan-Robinson
Although nitrox has been used for recreational diving for almost 25 years, it is still often misunderstood. As an instructor, I’ve found myself correcting countless students who are under the impression that nitrox enables a person to dive deeper than normal air — just one of the common misconceptions about nitrox diving. Although specific training is required before diving nitrox for the first time, these basic facts will help to make more sense of what it is and what it can do for you.
What Is It?
Quite literally, nitrox refers to a mix of nitrogen and oxygen, regardless of the percentage of each in the mix. The nitrox we use while diving is more properly called enriched-air nitrox, and refers to any blend of nitrogen and oxygen in which the oxygen concentration is greater than that of normal air. This means an oxygen level of 22 percent or higher, although the most common enriched-air nitrox blend is 32 percent. The recreational diving limit is 40 percent oxygen.
What Does It Do?
As every entry-level diver knows, increased pressure at depth causes the nitrogen in the air we breathe to be dissolved into the bloodstream. The time that we can spend underwater is limited by this nitrogen absorption — as we dive deeper and for longer, we absorb more nitrogen at a greater rate. Our no-decompression limit correlates to the amount of nitrogen our bodies can absorb before we must perform compulsory decompression stops or suffer the consequences of decompression sickness.
Enriched-air nitrox slows down the rate at which nitrogen dissolves into our bloodstream, because there is less nitrogen available to be absorbed from the mix that we’re breathing. The higher the percentage of your enriched-air blend, the more nitrogen is replaced with extra oxygen.
There are several reasons divers use enriched-air nitrox. One of its biggest benefits is an increased no-decompression limit, which means longer bottom time. The lower percentage of nitrogen in the nitrox you’re breathing means your bloodstream is also absorbing nitrogen more slowly. For example, on normal air a diver has a no-decompression limit of 50 minutes at 60 feet; using a 36 percent enriched-air mix at the same depth will extend this limit to 130 minutes. In terms of increasing bottom time, enriched air is most useful for depths between 50 and 100 feet; any shallower and no-decompression limits are already so long that divers usually have no need to extend them.
Surface intervals are usually shorter on nitrox as well. Since there is less nitrogen to off-gas, a diver on enriched air will be able to re-enter the water sooner than a diver using normal air after completing the same profile. This also means that divers using enriched air typically have longer maximum bottom times on repetitive dives, and less off-gassing means that enriched air divers are often less tired at the end of the day than divers using normal air. Enriched air can be a valuable safety buffer for divers who choose to use it while following normal air tables, computers, profiles and procedures. Doing so creates a considerable conservative margin that further reduces the risk of decompression sickness, and may be advisable for anyone who may be susceptible to it, such as those who are tired, overweight, older, have suffered decompression sickness before, or are diving with injuries.
Myths, Considerations and Dangers
Although the benefits of diving with enriched air are significant, doing so also involves certain risks. One of the most common misconceptions about enriched air nitrox is that users can dive deeper than with normal air; in fact the opposite is true. Under pressure, oxygen becomes toxic. The percentage of oxygen in normal air (21 percent) only becomes toxic at depths greater than the recreational limit, but the increased percentages of oxygen in enriched air mean that toxicity can become a problem at much shallower depths. Toxicity causes convulsions that put a diver at risk of losing his regulator and subsequently drowning. However, enriched-air courses teach divers how to work out their maximum operating depth using the percentage and partial pressure of the oxygen in their mix. As long as the maximum operating depth is adhered to, oxygen toxicity should not be a problem.
Oxygen also requires caution in the sense that it is an exceptionally flammable gas. Although standard scuba equipment is safe to use with air blends containing up to 40 percent oxygen, the process by which an enriched-air cylinder is filled often involves much higher concentrations. Partial-pressure blending exposes the cylinder to pure oxygen that is later diluted with normal air, and cylinders that are not treated for exposure to such high levels of oxygen can explode. Therefore, any part of the cylinder that comes in to contact with pure oxygen needs to be “oxygen clean,” and cylinders used for enriched air and normal air are not interchangeable. Enriched-air cylinders require decals or stickers to differentiate them from normal ones; they should be serviced annually.
There are a few other equipment considerations to bear in mind when considering enriched-air diving. Before each dive, you are personally responsible for checking the percentage of oxygen in your cylinder. If it is even slightly off, your maximum-operating depth calculations will be too. To check, you will need an analyzer, and although you can usually borrow one from your dive center, it’s a good idea to have your own if you intend to dive nitrox regularly. If you dive with a computer, you need to make sure that yours has enriched-air settings and correlates to the details of your mix before beginning each dive. Remember that enriched air does not improve air consumption, and neither does it give immunity to decompression sickness. Continue to check your gauges, depth and time limits as often as you would when diving on normal air.
With these precautions and the necessary training, enriched-air diving is a fantastic way to get the most out of your diving experience. You’ll spend more time in the water, and less time waiting to get back in.
Can Scuba Be a Good Workout?
By Jessica Vyvyan-Robinson
Although scuba is technically a sport, for most of us, diving is more about calm than cardio. One of scuba’s biggest attractions is the relaxation it offers, as well as the chance to escape from the frenetic pace of life on land. Most dives require very little physical work once underwater, and so it’s hard to think of scuba as part of a fitness regime. But a day of diving always leads to a good night’s sleep and a disproportionately large appetite, so perhaps we’re expending more energy underwater than we realize. Although diving requires a relatively low level of physical activity, other factors combine to make it effective exercise, which is good news for those of us who would rather spend our time beneath the waves than in the gym.
The conditions of the underwater environment are a considerable factor in scuba’s value as a fitness tool. Although you may not feel as though you’re exercising while diving, the water around you is conducting heat from your body 20 times faster than air, so you must work hard to maintain its core temperature. Even in tropical climates, metabolic activity increases significantly in order to combat heat loss; in cooler parts of the world, the body must expend even more energy to counteract frigid temperatures at depth. Some dives require more physical activity than others — anyone who’s ever had to contend with strong current knows just how tiring swimming against the flow can be. Similarly, keeping up with marine life, attempting to stay in one place for photography purposes, or any kind of underwater activity that involves hard finning results in additional calorie expenditure.
The technique used to fin properly, i.e. from the hip rather than from the knee, is key to strengthening core muscles as well as glute and back muscles, according to PADI’s director of communications Theresa Kaplan. She attributes diving’s toning and strengthening properties to the fact that water is a medium “hundreds of times more dense than air.” Water resistance is instrumental in defining scuba as a valuable form of low-impact exercise. Diving’s low impact also makes it a good alternative to conventional exercise for those with weak or injured joints, as it puts considerably less strain on the body than most land-based physical activities. Diving is therefore not only a good workout for healthy individuals, but also a great form of physical therapy for those recovering from injury. Some scientists even believe that scuba may decrease the time it takes for wounds to heal, thanks to the body’s consumption of concentrated levels of oxygen at depth.
Diving can also aid long-term fitness, as breathing techniques used to improve air consumption teach the body to absorb more oxygen for every inhale. Normally, the body uses only a quarter of the oxygen it inhales, but diving can increase lung efficiency over time. And the dive itself isn’t the only part of the sport that offers a workout. The routine of kitting up, carrying gear to the point of entry, getting in and out of the water and de-kitting also contributes to scuba’s overall fitness value. A dive cylinder weighs between 30 and 50 pounds; carrying a full scuba unit strengthens core muscles, particularly during shore entries. Lifting cylinders, weights and other equipment often involves actions comparable to weight-lifting exercises used in the gym. Diving is therefore not only a cardiovascular workout but a muscular one as well. According to the American College of Sports Medicine, the physical demands of diving are significant enough to be treated with caution; those suffer from significant health conditions or obesity should seek medical advice before attempting to dive.
The benefits of scuba to general physical fitness were acknowledged by the 2011 Compendium of Physical Activities, which compared it in terms of metabolic activity with ice-skating, power-walking and casual soccer. On average, a man weighing 180 pounds can expect to burn as many as 600 calories during an hour dive, and many more if swimming in strong currents or particularly cold water. Several online calculators can work out the calories burned during a specific dive, based on weight and the time spent underwater.
Scuba is beneficial not only as a viable form of physical exercise, but also for mental and emotional wellbeing. The peace, serenity and beauty of the underwater world encourage positivity and give real joy to those who experience them. Diving is a great way to tone and strengthen your body, burn calories and boost your serotonin levels, ultimately making it both a rewarding and enjoyable way to keep fit.
Five Frogfish Facts
Credits to PADI
Frogfish are masters of disguise. Spot one during a dive and you will win the admiration of every diver in your group – especially photographers. Frogfish, a type of anglerfish, have a textured exterior that aids in their camouflage. While they do not have scales, their amazing ability to camouflage themselves serves as protection from predators. Frogfish vary in color and often have unique spines or bumps that change with their surroundings.
Here are some more interesting frogfish facts:
1. Unlike many animals that use camouflage as a defense from predators, frogfish mostly use their abilities to attract prey.
2. Frogfish have a modified dorsal fin that has a retractable lure resembling a shrimp, which is used to attract their prey. If their lure is eaten or damaged it can be regenerated.
3. Frogfish are carnivores. They eat fish, crustaceans and even other frogfish.
4. A frogfish’s mouth can expand to 12 times its resting size. This allows it to catch all sorts of prey.
5. Because frogfish lack a swim bladder, they use their modified pectoral fins to walk, or even gallop, across the seafloor.
There are many fish in the sea that use camouflage, but the frogfish is a real treat to see. Frogfish can be found in tropical and subtropical oceans and seas off the coasts of Africa, Asia, Australia and North America. Next time you take a dive in one of these regions take a closer look at the reef.
Have any frogfish spotting tips? Post them as a comment below…