Water is amazing stuff. For every ten meters of descended depth away from normal atmospheric pressure, it exerts 14.7 pounds per square inch of pressure per square inch. This pressure is felt only slightly on the outer surfaces of the body, but in cavities filled with air, it is felt much more strongly – and those feelings of pressure increase as one descends to greater depths, even if those depths are only in a swimming pool. Here, we’ll take a look at pressure and how to deal with it by equalizing – a very important basic scuba skill.
The Basics of Equalization
While all scuba skills are important, equalization is one that won’t just prevent you from injury, but one that will keep you from feeling uncomfortable while diving. If you’re only now considering becoming a certified scuba diver, you may not know what this pressure feels like, but there are a few common circumstances during which you may have felt something similar. If you have ever been to the bottom of a deep swimming pool, you may have experienced feelings of pressure inside your ears and sinuses; if not, you may have experienced these feelings when driving over a tall mountain or flying in an aircraft. While the feelings of decreased pressure that come with increased altitude are the same as those you’ll feel while submerged in deep water, they are somewhat similar since the same body cavities are affected during both sets of circumstances.
When a diver descends into a body of water, the tympanic membranes inside the ears begin to stretch; in the event the diver fails to properly equalize, it is possible for these membranes to rupture due to the pressure caused by the surrounding water as well as the pressure differences between the middle and inner / outer ears. Even if the eardrums do not rupture, intense pain can occur; this is a symptom of damage being caused to delicate organs inside the ear. If air pressure is not balanced inside the sinuses, severe pan may also occur; this can be a symptom of damage occurring inside sinus cavities. Both ear and sinus injuries caused by excessive pressure are called barotraumas; if you feel discomfort and cannot equalize, it is vital that you ascend a bit to reduce the pressure and lessen the potential for a serious injury that could lead to permanent hearing loss and other irreversible damage.
Another air-filled space divers must be cognizant of is the space inside the mask. During basic scuba instruction, you will learn how to equalize this space by breathing carefully through your nose to change the air volume inside your scuba mask.
When ascending, equalization is equally important. During ascent, the pressure inside the middle ear must be relieved as it is greater than the pressure of the shallower water you’ll be ascending through. Fortunately, our Eustachian tubes release gases as they expand, so long as we ascend at a slow, controlled rate. This natural body function sometimes does not work properly in divers who have swollen Eustachian tubes, either due to damage caused by repeated dives, an infection, or some other physical problem. When there is swelling, normal equalization techniques may not work, and in some cases, they can cause further complications. This is referred to as a reverse block; if it happens, you will feel ear pain during ascent, and you will need to descend slightly to alleviate the pressure and wait for the excess air to leave your Eustachian tubes.
Remembering that pain or even discomfort in your ears is the first sign of potential barotrauma while diving and ensuring that you take immediate action to correct the discomfort can prevent serious injuries from happening in many cases. During basic scuba training, you will learn how to alleviate this discomfort by using various equalization techniques, including those that follow.
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The Vasalva Technique – This equalization method involves holding the nose, closing the mouth, and then gently blowing air into the closed nostrils. Many novices wind up squeezing the muscles that surround the Eustachian tubes, which makes equalization difficult; some blow too forcefully, which when done repeatedly, can cause air bubbles that will result in barotrauma.
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The Tonybee Maneuver – To effectively conduct the Tonybee equalization technique, one pinches the nostrils, then makes a swallowing motion with the muscles in the throat. This pulls the Eustachian tubes open while the movement of your tongue compresses the air surrounding them. When using this method, it’s vital not to swallow any air. If air is inadvertently swallowed during the Tonybee maneuver, gastric complications can occur during ascent; in the most severe cases, stomach rupture can occur.
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The Frenzel Technique – Pinch your nose closed. Using the rear portion of the tongue and the throat muscles to close off the throat, make the sound of the letter “K” which will force the back of the tongue upward, compressing air against your Eustachian tubes.
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Edmonds Technique – While tensing the soft tissue at the rear of the roof of your mouth (soft palate,) push the jaw down and forward, then utilize the Vasalva technique.
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Lowrey Technique – In the Lowrey equalization technique, you combine the Tonybee and Vasalva techniques, closing your nose, swallowing, and blowing at the same time.
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Voluntary Tubal Opening – This method requires plenty of practice to perfect, however many seasoned divers are able to utilize it with ease. It involves tensing the soft palate and throat muscles while thrusting the jaw forward and down in the same way you would when starting to yawn. These muscles will pull your Eustachian tubes open to release pressure.
Train yourself to check for the clicking or popping sound you’ll hear when you conduct these maneuvers; when they are done topside, you’ll hear a noise that tells you that your Eustachian tubes are open. When diving, start equalizing several hours beforehand, which can help to prevent blockages that sometimes happen during descent; simply chewing gum can sometimes help.
As with other scuba skills, practice makes perfect. It is a good idea to learn how to use several different equalization techniques so that you can try more than one in the event you have difficulty equalizing. Unlike many of the skills you will learn, these can be done anywhere. You’ll find many videos and online tutorials available to help you with practicing; spending some quality time learning to equalize before you ever dive deep will help to keep you safe and healthy.