Equalizing for Freediving and Scuba

By Kirk Krack

If you’ve taken a diving course, be it scuba or freediving, you would have been taught the process of equalization. You equalize to ensure that your ears, sinuses, and mask are equal to the water or ambient pressure surrounding you at your depth. Most scuba courses start with: “Pinch your nose and blow as if blowing your nose through a tissue until you feel your ears pop. If this doesn’t work then also wiggle your jaw and tilt your head side to side.” Then it’s straight into the pool to give it a try. If you did a proper freediving course you likely spent 90 minutes of classroom theory and workshop practice followed by a slower progression of developing the ‘art’ of equalizing. It’s an art for freedivers because freedivers only have the volume of one set of lungs-worth of air to allow equalizing to happen, and that lungful is being compressed (i.e. made smaller) as we descend. Also, the speed at which a freediver descends and a freediver’s head position can complicate the process.

Basic Physiology

As divers, we have three types of airspaces in our bodies—this includes both the natural spaces and the artificial that come from our equipment: ridged (ears, sinuses, mask); semi-ridged (trachea, bronchus and bronchi); and flexible (alveoli, bronchioles and gastrointestinal). For this article we’ll focus on the ridged airspaces of ears, sinuses, and mask, as the others tend to take care of themselves or deserve their own article. 

As we descend, the increasing water pressure ‘pushes’ on these airspaces, ‘flexing’ them. A minor degree of flex and we feel it without any pain or discomfort, signalling us it’s time equalize once again (should be completed every three to five feet (1-1.5m) and before any discomfort happens). If we ignore the flexing sensation or don’t equalize successfully then we may feel a discomfort and/or our ears may ‘squeal’ (large air volume being forced through a small opening), which is a good indication we’ve waited too long. If we continue to ignore the ‘flexing’ and the discomfort or squeal then we start
to experience pain and by this point any equalizing is likely to cause minor to major barotraumas (pressure related injuries). So it’s important to equalize early and often, and before needed (pre-equalizations) to avoid any problems.

Valsalve vs Frenzel vs VTO

There are a myriad of equalizing techniques, some of which are suitable for scuba (but still not the best) but really don’t work for freedivers; some are the bread a butter for freedivers. Very few divers have the gift of being able to enjoy the Holy Grail of equalizing. 

Typically a scuba course teaches the Valsalva manoeuver (“pinching your nose and blow”) because it’s a quick and simple method to describe and can be somewhat adequate. It involves taking a volume of air in your lungs and blowing that out gently against pinched nostrils, thereby (hopefully) directing the air into the ears. However, Valsalva becomes ineffective for a freediver below 33 feet (10m) because at this depth the freediver’s lungs are now half their surface volume. At 66 feet (20m) they are a third of their surface volume…and so on. Give this one a try: exhale everything (simulating 133 feet/40m or having 1/5th the lung volume) and try using Valsalva. It’ll be difficult for some and impossible for most to equalize effectively. 

From the start, freedivers are typically taught the process of Frenzel technique, in which the throat becomes a piston to push air into the airspaces. It’s more effective, using a smaller amount of air, creating higher pressures and using much less energy, while also bypassing the compressing lungs. So, if as a freediver you equalize fine in shallow depths but find it hard to equalize effectively past 33 feet (10m), you may need switch techniques. 

So how do you know which one your using already? Simple, put your hand on your stomach and equalize your ears. If your stomach moves or tenses then you’re likely using Valsalva. Now put your hand on your throat. Does it move? If so then you’re likely using Frenzel.

 The Holy Grail for freedivers is VTO or Voluntary Tubular Opening. You know these divers, bragging all the time how they don’t have to pinch their noses as they just ‘swallow’ or ‘do something’. That something their doing is activating their palatini muscle to open the eustachian tube (connecting sinus to middle ear). With VTO you are no longer ‘forcing’ the air into the middle ear, but are simply opening the door for it to equalize itself. My wife, Mandy-Rae Krack, can attribute part of her seven world freediving records to this ability and I am more then jealous. Although it can be learned, most of the people who equalize via VTO have an innate ability to manipulate this muscle somewhat already. For those of us who can’t, it’s better to perfect Frenzel.

Technique vs Physiology

A number of problems can arise when equalizing. These may be momentary or they may be chronic. They may be the result of lack of technique or something physiological. Regardless, perfecting and practicing good technique with exercises can generally alleviate either. So what do you have, a technique or a physiological problem? Break it down like this. Is the problem one ear or both ears? If you have one ear that gets stuck and won’t equalize but the other is fine then it’s generally a physiological problem with that one ear. If both ears have problems then that is generally a technique issue. 

Regardless of which it is, learning a good Frenzel technique is important, along with daily exercising. The exercise is to equalize dry two-hundred times daily. This will perfect your technique, coordinate the movements and muscles involved, and create flexibility within the eustachian tube to allow an easier passage of air. I prefer to do it in blocks of ten continually through the day.

Problems & Solutions

Problem: Ears get slower equalizing as I dive

Solution: Snort after every dive—unlike scuba divers, an average freediver in 50-100 feet (15m-30m) in an average day will equalize 1500 times, whereas the scuba diver will equalize a couple hundred. Sinuses are also designed to move air inwards and are always producing mucus; however, the simple act of nasal breathing moves it away—until you put on a mask and don’t breathe through your nose. So when you get to the surface, especially as a freediver, pull your nose pocket away and suck (snort) or blow your nose to clear the mucus before your next dive or you risk slowly pushing it into your eustachian tubes and developing problems.

Problem: The first 15 feet (5m) is always a problem

Solution: Pre-equalize—as a freediver completing a proper entry, we can get to around ten feet (3m) before we’ve even gotten our hands to our nose. So just before starting your entry, pre-equalize and get at least the first ten feet (3m) out of the way.

Problem: One ear is always slower and eventually ends up stopping

Solution: This one is two-fold: develop Frenzel and practice dry two-hundred times daily; also push against the tear-duct on the eye that is the same side as the problem ear. Test this one out: equalize dry and hold a sustained pressure, do you feel air escaping your tear duct? If so, then in the path of least resistance to equalize your ear, air is escaping via that tear duct. The solution is to block off the tear duct, thereby forcing the air to go through the eustachian tube and conditioning it over time. With practice it will become the path of least resistance.

Some people naturally have on ear that’s slower to equalize than the other. We tend to focus on the first ear that equalizes fully and stop trying to equalize when this ear clears. Instead, concentrate on getting a full equalization on the ‘slow’ ear and don’t stop until that one is equalized.

Problem: I can equalize fine head-up but can’t when head down

Solution: Work your soft palate (your soft palate is that fleshly flap at the upper back of the mouth that is the problem if you snore). When you descend head-down, it falls to the back of the throat, closing off the air delivery to the sinuses and then the ears. You can work your soft palate by doing long and slow inhalations and exhalations while switching the air between the mouth and nose. This will engage the soft palate so you can feel it and gain control over it. Another thing you can try is to get into a head-down position (this can be dry hanging over a table); if you are unable to equalize, suck your mask onto your face (this will break the soft palate) and then try to equalize. It may take some practice and guidance from a professional instructor to help you navigate this exercise.

Problem: when equalizing at deeper depths I ‘lock up’ with both ears

Solution: Practice equalizing two-hundred times a day and make sure you’re releasing your nose between each equalization. If your ears are doing fine then suddenly lock up, likely you are forgetting to release the nose pocket, causing the mask to go negative and then when it releases it sucks the soft palate against the back roof of the mouth.

Final Thoughts

While we can’t cover everything here, I hope you have a better appreciation of equalizing, both on scuba and freediving. Simply ‘pinching your nose and blowing, and then wiggling your jaw’ is inefficient instruction. Take the time to learn proper technique. If you’re a scuba diver, think of a freediving course as continuing education and cross-training that can help you to better your preferred method of underwater exploration.