Friday, May 4, 2018

Diving Fundamentals: Equalizing and Alternative Techniques

It's a fundamental principle of diving that water is denser than air. Consequently, when you move up and down through the water column there is a greater proportionate pressure change than changing elevation in air. Instructors advise scuba students from the very first class that equalizing early and often is crucial to avoid discomfort.

It's easy to equalize artificial air spaces such as your mask and drysuit by simply adding air regularly during descent in proportion to ambient-pressure changes.
The lungs — given that a diver breathes slowly, deeply and continuously — are self-regulating. The equalization process takes care of itself instinctively. However, the body's ear and sinus air spaces can be more temperamental. Many divers experience discomfort or injury in those early dives if they do not equalize effectively or force the issue.

When pressed, most divers could probably describe how they equalize their ears and sinuses. A smaller subset may be able to name their preferred method, and an even smaller subset might name several alternative methods which may prove effective.

We're all subtly different when it comes to our physiology. What is effective for you may not work for your buddy. There are a range of methods when it comes to equalizing, from common to alternative techniques. Here are a few of the most common.

Back to basics

The art of equalizing ear and sinus air spaces is to do it early and often. As you gain experience, doing so will become instinctive. There are three main techniques for equalizing these areas.

  • Blow gently against pinched nostrils

Known as the Valsalva technique, this is the first one you'll learn and often the most effective ways to equalize. Pinch your nostrils closed with your fingertips and with your regulator in your mouth, blow gently as you would blow your nose into a tissue. The process adds air to your middle ear, helping you equalize. Miming this process also works to help your buddy do likewise if they seem to be struggling.

  • Rotate the jaw

Wiggling your jaw in a circular or side-to-side motion can also help you equalize air spaces as you descend.

  • Swallow

The simple act of swallowing helps to redistribute air and equalize air spaces.
Depending on your own physical traits any one of the above — or a combination of all three — may work effectively for you. Although the Valsalva method is the most common, there are a few alternatives to consider as well.

Alternative equalization techniques

Yawn and tilt

Keep your throat and jaw tensed and then slide the jaw forward and down as if yawning. This technique of a 'modified yawn' helps ease the eustachian tubes open. Try tilting your head from left to right — you may find the elongated side of your head/neck is easier to equalize.

Edmonds technique

Push the jaw forward and down while tensing the soft palate and throat, similar to yawning. Then pinch your nostrils and blow out gently as with the Valsalva.

Toynbee maneuver

While pressing your tongue against the roof of your mouth, pinch your nostrils closed and then swallow.

Lowry technique

Using a mixture of both Toynbee and Valsalva, close your nostrils, blow and swallow at the same time.

Frenzel maneuver

Close your nostrils and the back of your throat, then make a deep, prolonged grunting or growling sound. The grunting sound may help ease open the airways. This is a variation on the Toynbee method.

For further details on alternative equalization methods, and a look inside the ear as it takes place, take a look at this excellent video from Dr. Frans Cronje of Divers Alert Network:

Stay refreshed

Before a diving trip, refresh yourself on the basic rules and recommendations. 

  • Relax before the dive. Address any concerns you may have with your buddy, dive leader, divemaster or instructor. Don't let anxiety overwhelm you. 
  • Don't dive with a cold or congestion that will adversely affect the migration of air in your body's air spaces. 
  • Descend in a slow and controlled manner when possible. Give your body time to adapt and equalize as necessary. 
  • Equalize early and often – before you feel any pain. Don't wait until you actively feel the sensation of increased pressure or a squeeze. Equalize regularly throughout your descent regardless or whether or not you feel any sensation of squeezing. 
  • Don't descend head down if you can avoid it. There's significant evidence that equalizing is more effective in a horizontal position or head-up position. 
  • Use a line to control your descent if one is available. Grasp the line with your right hand so you can adjust buoyancy with your left hand, pause, signal your buddy and control your descent. This allows you ample time to equalize. 
  • If making a free descent in open water, position yourself for effective equalization. Retain your jacket's low-pressure inflator in your left hand while you leave the surface and make your initial descent. Leave your right hand free to pinch your nose. 
  • If your techniques are ineffective, swim very slightly shallower (3 feet/1 m) and try again, descending very slowly. Going violently up and down several feet or meters will only exacerbate the issue. Small buoyancy adjustments and continual equalization are more effective. 

Equalizing effectively may require slightly different methods depending on the individual diver. Try different methods to find what suits you and you'll have a more comfortable and successful dive as a result.

 

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