Notes about things regarding scuba diving that I have come to know
Skin-Diving, The Essential Foundation to SCUBA Diving
What is skin-diving and why do I have a topic devoted to it on a scuba web site? Skin diving in my opinion is the ultimate gateway sport to scuba diving and provides an excellent foundation from which to learn the sport. Where skin-diving used to be mastered in scuba training it is now glossed over all too frequently leaving students overwhelmed with new equipment and lacking in basic skills.
First Some Definitions
Snorkeling, skin-diving and free-diving are terms that are frequently interchanged and one would be hard pressed to find formal definitions that differentiate between the 3 terms. In context some definition is possible but anyones execution of the sport can blur the lines and that's just fine.
Snorkeling as the name implies involves breathing through a snorkel while observing the underwater world through a dive mask and propelling ones self with dive fins. A snorkeler may be in a swimsuit or be wearing any level of sun, sting or thermal protection. The sport is generally a passive sight seeing pursuit. The snorkeler may dive down while holding one's breath to get a closer look at things but it's primarily a surface sport.
Skin-Diving Is really just snorkeling on steroids and straddling the 2 is very possible. Again what you call yourself is irrelevant. A skin-diver may be a hunter for instance. The skin-diver may be wearing dive weights to neutralize some of the buoyancy of a wetsuit. The skin diver is several pieces of gear away from being a scuba diver.
Free Diving stands alone as a competitive sport. Free divers seek to dive deep and or long depending on their individual goal. It can be a recreational or competitive sport. A free diver may forgo the use of a snorkel. They will use an ultra low volume dive mask to lessen the air required to equalize for mask squeeze. Their fins will be long and powerful at the cost on the maneuverability conventional fins work to offer. Competitive free divers range from swimming down and up unassisted to using weights to plunge deep and air bags to rocket back to the surface.
If you are out on the water with a mask, snorkel, fins and perhaps more call yourself whatever you want, just keep doing it.
So with those definitions out of the way what makes me so up on skin-diving? I feel a skin-diving foundation is so important that if it were up to me each scuba student would train for and make an open water skin-dive before ever touching a buoyancy compensator (BC), regulator or cylinder of compressed air.
So Why start with Skin-diving?
- Fundamentally as humans it is just plain wrong to be breathing with our faces in the water. Some scuba students have a history of water sports or are naturals. Others need some time to get comfortable with breathing while their face is submerged. Skin-diving offers limitless opportunity to develop this comfort.
- Most of us are not strictly oral breathers. Most of us breathe largely through the nose. In scuba and skin diving we rely on 100% oral breathing. Once again the ease with which a scuba student makes this adaptation varies. Investing time in skin-diving will program the diver to breathe orally when their face is in the water. This will prevent a host of annoyances that can come from exhaling into the mask or from trying to inhale with the nose let alone anxiety.
- Skin-diving will train you to breathe effectively. When scuba diving you have a finite amount of air available to breathe. If you breathe effectively you will enjoy a longer dive. When diving it is important to take deep breaths in order to get fresh air deep into your lungs. What is even more important is to exhale deeply in order fully vent carbon dioxide from your lungs. The level of carbon dioxide in your blood is what you sense and that compels you to breathe. You are not triggered to breathe because you have consumed the oxygen in the air. Even on the surface there is plenty of oxygen left in each exhaled breath. When diving we are in a hyperbaric state. At 33 feet for instance there are twice as many molecules of oxygen at our disposal. Effective scuba breathing is all about carbon dixide management. By exhaling slowly and fully you can comfortably dive and use less air. If you exhale incompletely carbon dioxide will build up in your blood and you will begin to breathe faster. Soon the gas exchange will be so poor that you will feel like you cannot get enough air when in reality you are loading up on carbon dioxide. This can bring a diver to a state of panic. Slow deep effective breathing will keep you at ease and use much less air than fast shallow breaths. Do not get trapped into thinking that nice deep full chest inhalations will drain your cylinder, it's quite the opposite and will serve you well over the course of your dive.The difference can be as great as 2:1 between divers though other factors will also contribute. Do you want a 30 minute or a 1 hour dive? This is probably more than you need to know for skin-diving alone but it illustrates the benefit of skin-diving for a scuba diver candidate.
On top of that by breathing poorly and accumulating carbon dioxide in you blood you will probably end your dive with a whopping headache. Proper deep breathing will prevent this. Breathe deep and as you become comfortable in the environment the slow part will probably happen on it's own. This is not about depriving yourself of air.
So what does all of this have to do with scuba diving? Well a snorkel has one big design flaw that will work to your advantage. That snorkel as well as your mouth and trachea represent dead air volume. All of that air must exit the end of the snorkel before any of the stale air in your lungs can exit your extended respiratory system. Likewise any fresh air you get must come all the way from the end of the snorkel. If you take a snorkel and take very short breaths the same air will be going up and down your windpipe and you will eventually suffocate. This is an extreme example. Obviously you will not allow yourself to suffocate while breathing from a snorkel. Before that happens you will lift your face from the water and spit the snorkel out gasping for air.
What will happen is that you will quickly adapt to long deep effective breaths that effectively exchange the air in your lungs despite that pesky dead volume of the snorkel. Since your carbon dioxide level will be low you will find that your breathing rate slows unless you are out of shape or swimming hard.
The magic will happen when you swap the snorkel for a regulator mouthpiece, slip below the surface of the water and breathe in that same slow deep effective manner. As you become at ease diving your air consumption will be noticeably lower than many. This may mean longer dives or you can enjoy diving with a smaller cylinder which makes it all easier and guess what? It saves even more air!
- Setting aside the assorted swimming skill requirements it is most important that a diver be comfortable in and on the water. Making skin-dives in various open water locations gets students out on the water while in a safely buoyant state.
- The snorkel has even more magic! In order to breathe we create a pressure change by flexing the diaphragm muscle in our lower chest. This causes air to move in or out much like a fireplace bellows. Sitting here reading you are all at the same pressure; your mouth, your chest, everything is at one atmosphere and things work in equilibrium. In order to draw a breath from a scuba regulator a pressure change must be detected by the second stage. This is commonly measured in "inches of water column" and in order to initiate a breath about 1 inch of force is required. This is very slight and feels very natural.
When skin diving your snorkel is up in the air at one atmosphere but your chest is down in the water and while swimming your lungs are centered several inches below the surface. This means that you are working against those several inches of water column in order to breathe. If you bob vertically with your mask and snorkel so that your lungs are 8-10 inches below the surface you will be able to detect this work of breathing.
Frequent skin-diving strengthens your diaphragm muscles and allows you to better control your breathing. This is important for respiration and buoyancy control. You can even buy a mouthpiece with a restricting valve to breathe through with the intent of getting the same result but getting wet is much more fun.
Just as skin-diving can strengthen your diaphragm and promote effective breathing so can singing. You probably know that a big part of formal vocal training is learning to effectively manage one's breathing. The good news is that in order to become a better diver you do not need to sing well you just need to breathe good while trying.
If like me you cannot carry a tune, even in a bucket then this is best reserved for when you are alone in the car or otherwise in solitude. Find some music you know the words to and have at it. Sing loudly and with verve. Go for those long notes and see how many bars you can go on a single breath. Falseto, lead or be the bass line, it's all good. Passing drivers will think you are the life of the party and you may even find a karaoke junkie hidden within your inner self.
In addition to being good dive training it's just plain good and healthy for you. Getting your lungs flushed and filled with fresh air is a great stress reliever and lets me begin my day energized and arrive back at home ready for the evening. It also makes my kids cringe when they have friends in the car.
As you can see much of what you need to be capable of as a scuba diving can be practiced in advance while skin-diving. Without the heavy weight of the scuba rig it becomes easy to get comfortable with all of the fundamentals. With some coaching from your instructor or with your own reading you can practice any time in open water or in any available pool before you take your first scuba class. With all of the skin-diving skills in place it becomes easy to learn use of the regulator, air cylinder and buoyancy compensator
- Jumping into a pool to start scuba training with a mask that does not fit well can be a torturous experience. If you have already been out skin-diving and have sorted out any mask issues there should be no problem when you swap your snorkel for your regulator mouthpiece. There can be exceptions such as very meaty regulator mouthpiece that will exaggerate some facial folds. Mouthpieces are easily changed and some classes will actually require you to buy your own and install it for every session.
- It is entirely possible to clear your mask while skin-diving and breathing with the mask off is also easy to work into your skin-diving routine. These are basic scuba requirements that can be mastered before you touch a regulator.
- Just getting into a wetsuit, booties, hoods and gloves can be an unnerving experience for a new diver. Standing around in skin-tight rubber, the slight compression of a well fitting suit, let alone the hood and gloves can take some getting used to. This sort of anxiety is not what you want if you have any reservations about trying to breathe while underwater. Skin-diving provides a good chance to sort out any fit problems as well as getting effective at donning and doffing your suit all in a low stress situation.
- Many new divers have trouble controlling themselves in the water because the use of dive fins requires practice. Equally common are debilitating leg cramps due to new loads being placed on leg muscles. By starting with a good amount of skin-diving you can learn to control your body with a twist of your ankle and a flick of your fin. This will get you on your way to being a more graceful diver and you will rely less on hand movements. Excessive arm movements are wasted energy which costs you air and the movement also encourages water movement in your suit which will cost you body heat. By doing a fair amount of skin-diving you will condition your leg muscles to deal with the load placed upon them by dive fins. This will greatly lessen the chance of a mid dive leg cramp.
- Part of learning to pike down is learning to equalize your ears. It only gets easier while scuba diving but even for scuba students it's a frequent stumbling block. As a proficient skin-diver you will enter scuba training full capable of clearing your ears. The same is true for mask squeeze, an almost certainty in skin-diving.
- As a skin-diver you will probably learn to use a weight belt to counteract the buoyancy of your wetsuit. Learning to handle the belt is another scuba skill you will have mastered before you start.
- As you learn to dive down to investigate sights or perform activity you will build confidence in handling yourself underwater while holding a breath of air. When it's time to remove your regulator for retrieve and replace drill you will be much more at ease. To avoid an embolism when using scuba gear remember to always constantly exhale lightly anytime your lungs have been filled with compressed air.
- Skin-diving will get you into your local water. It will let you enter the theatre lobby and catch some previews through the screening room door. When you enter the water for your check-out dives you will have some idea of what the underwater world looks like. With those visions in the back of your mind you will have a magnificent motivational tool to get you through any challenging skill drills.
As a fellow diver it's not my place to tell you how to skin-dive. I learned on my own as a kid and learned some finer points as an adult through reading books and on ScubaBoard where a forum is dedicated to "Snorkeling / Freediving" and I continue to learn. Any local or resort dive center can offer a brief lesson in what you should know. I keep my dives generally near shore where I have visibility to the bottom since swimming over a expanse of clear water is not very interesting. Sometimes a crossing to another area is worthwhile and that provides a good reason for an intense swim. I personally consider skin-diving to be a safe solo sport with the caveat that you limit your dives to the bottom. Be sure to understand the term Shallow Water Black-Out before heading out on your own. Many of the benefits I mention can be derived doing laps in a local public pool. Getting into open water will let you get accustomed to your exposure protection and actually enjoy a preview of the world that awaits you as a certified scuba diver.
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This page created August 8, 2007
Edited May 21, 2008