The recommended equalization technique for freedivers is the Frenzel maneuver. The Frenzel is favored over the Valsalva, which is more commonly used by scuba divers, because the Valsalva maneuver uses greater force, and requires more effort and lung flexibility. There is another maneuver that receives less attention and is often not taught to freedivers – the hands free maneuver or the Beance Tubaire Volontaire (BTV) in French, or Voluntary Tubal Opening in English. It involves the contraction and holding of that contraction of the soft palate muscles and upper throat muscles to hold the Eustachian tubes open (Roydhouse, 1993). The opened tubes allow for the equalization of pressure between the nasal cavity and the middle ear cavity, as air would automatically travel from a region of higher to lower pressure. Hence, unlike the Vasalva or Frenzel where air is pushed up by the chest/diaphragm or tongue/throat respectively through the Eustachian tubes into the middle ear, the BTV is a gentler alternative.
According to experts, this method is difficult to teach and only possible for those born with favorably formed and shaped Eustachian tubes (Roydhouse, 1993). Dr Noel Roydhouse estimated that 50 per cent of divers could learn the BTV (Roydhouse, 1993). Dr Edmund Kay, a popular ear barotrauma expert, was less optimistic and found that only 30 per cent of those he had taught were able to perform the BTV reliably (Kay, 2000). Equalization expert, Federico Mana, is even more pessimistic and does not believe that BTV can be learned “simply by exercising” (Mana, 2011, p. 95). Despite these disappointing verdicts, experts agree that the BTV is the “safest maneuver” and the “ideal maneuver for economy of movement, relaxation and energy conservation” (Mana, 2010, p. 96). Whether or not one eventually learns or masters the BTV, becoming familiar with the muscles that hold the Eustachian tubes open is helpful to all divers, regardless of the pressurization techniques they use, as activating these muscles to untighten the Eustachian tube opening during equalization reduces the force needed for equalization.
In this post, I hope to challenge some myths about our understanding of hands free equalization, because in my search to understand how to perform this technique, I have found it shrouded in mystery. Experts will only say as much as what I have mentioned above, that it is difficult or impossible to teach people to perform the maneuvre reliably. Recently, attitudes have started to change. Andrea Zuccari recently release a YouTube video in Italian promoting the idea that anybody without functional or anatomical disability in the Eustachian tubes can learn to do the hands free (Zuccari, 2016). Adam Stern had produced a Youtube instructional video on it. This method is also used by other high-performing athletes such as Umberto Pelizzari (Campbell, 2016), Loïc Leferme, and Guillaume Nery (Chapuis, 2006). Besides these more advanced freediver, there are many other recreational freedivers who equalize hands free and some of them do share their own knowledge and experience in freediving and spearfishing forums.
This blog post is a combination of what I have learned from reading up about hands free equalization through these online forums and my own personal experimentation with it. Subsequently, I answer three key questions those who are interested in learning the hands free might have:
First question: What is the depth limit of the hands free? This is an important question, because of rumours that there is a depth limit to hands free equalization, which makes people wonder, “Why learn it at all?” So I did a small “survey” asking friends who can do the hands free how deep can they go and also taking figures of people from three threads of the DeeperBlue forum. This is in no way systematically done, but anecdotal. The figures included 10m, 24m and 50m from my friends. On the forum, we get numbers like 30m, 36m, 38m (unirdna, 2003), 30m, 44m, 30m (donmoore, 2004), and 60m (azapa, 2008). Based on these 10 data points, the average depth achievable by the hands free is 35.2m. So if you have properly mastered the BTV, expect to be able to go down to around 30m. Those who want to go beyond their personal hands free limits, typically begin to do a combination of hands free with the Frenzel or begin doing the Mouthfill.
Second question: What are the steps of equalization for the hands free? Beyond opening the Eustachian tubes, we need to also think how this process will change according to depth and pressure changes. What many people may not realize is that air shift techniques, essential to the effective performance of the Frenzel maneuvre, are also important in hands free. Before reaching residual volume, one need not keep the glottis shut, but just relax and open the Eustachian tubes and the pressure will equalize itself. However, you might find it easier to hands free if you begin shifting air into your mouth earlier. This also prevents the uncomfortable sensation of the mask pressed against your face as you approach residual volume. After reaching residual volume, I would assume the principles behind hands free equalization are the same as those in the Frenzel equalization. You will need to constantly shift air into your mouth to continue to equalize to further depths.
Third question: How do you learn and practice the hands free? This is an important question for those who are curious and want to give it a try. Though our anatomy does play a part in determining how easily we learn different equalization techniques, I believe it can be learned to a certain extent, the way we may have learned to suppress yawns, to sing in high pitch, and to wiggle our ears. For those who managed to fine-tune this ability, they described learning to hands free as attaining a skill. For example, Nick F (2015) used to be only able to do it on the couch, but over time “with a lot of experimenting and practice” he also learned to do it in the water. He now believes that anyone can do it:
“I think about it like learning to whistle. It’s a very difficult thing to teach. You can describe to a person generally how whistling is done, and some small percentage of people will pick it up almost immediately. But for most people, you have to start with what you’ve been told and play around with it until you stumble across what works for you. Once you know what that feels like, then you can practice…
The only reason I’m bringing this up is because most people seem to talk about BTV like it’s something you can just do naturally or not at all. If that’s not the case, I think it would be a shame to discourage divers from trying to learn it because they assume they can’t.”
How then can we practice? Being sensitive to and mindful of how it feels like when our body involuntarily equalizes during a yawn or swallow is often described as the first step. Our body is always equalizing the airspaces involuntarily when we eat and swallow, as there will always pressure differences created between the nasal and the middle ear cavities that will need to be equalized. So your body is by nature capable of doing it on its own, without your knowledge or permission. How then do we make what is done for us involuntarily, voluntary? A convenient and effective way to do so is using a method recommended by Laminar (2008), a forum writer:
“A simple way to work on your BTV is to reverse equalize your E-tubes. Pinch your nose, and suck air out of your E-tubes by filling your mouth or using your diaphragm… My tubes crackle as they depressurize.
Then to bring your E-tubes back to full pressure, start to yawn. Try varying degrees of yawning to get there. Eventually, you want to not yawn at all. Just move the muscles that let air back into the e-tubes.”
This method was how I started experimenting with hands free equalization. After being able to isolate the movement, I practiced it more and more to make it cleaner and cleaner. Since the draft of this article was first written on the 11th of August 2017, I have made some progress myself, with a week-long trip to Gili Air to work on hands free equalization later in the month. You can read more about how I improved my own technique here. However, if you really want to learn it, do refer to Adam Stern’s instructional video. He is a good teacher.
I just wanted to show you how it looks like. (Pardon my poor diving form.)
Constant Weight with Fins using BTV in August 2017. Notice my flailing arms. If you noticed, there was a few times I stopped finning and held onto the line. This was me “braking” because my equalization was not yet efficient and required time and more conscious effort. With practice, the hands free efficiency does improve.
I would like to update that since then, I have also picked up the Frenzel in March 2018, and I am currently at the stage of figuring how to go confidently deeper after attaining residual volume. In this interesting video taken in April 2018, after handsfreeing down the line, I switched to Frenzel, I was unable to hands free anymore apparently… why?
That’s a mystery for me to solve next.
For now, all the best with the hands free! 😉
Update on 1 May 2020: I wrote Learning to Hands Free Equalize detailing how I exactly taught myself to BTV. I have since met many freedivers who are experienced with the Frenzel technique but have learned to Hands Free Equalize on top of it as well. I have even witness my friends making that progress in the water. It is definitely possible to learn it. What you need is patience, curiosity and time.
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To read more about hands free (BTV/VTO) equalization, check out the following links:
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azapa. (2008). BTV (Hands Free) dry tips and techniques please in DeeperBlue Forums. Retrieved 11 August, 2017, from https://forums.deeperblue.com/threads/btv-hands-free-dry-tips-and-techniques-please.78528/
Campbell, S. (2016). Freediving legends: Umberto Pelizzari. Retrieved 24 May, 2018, from https://www.youtube.com/watch?v=ltb0Hl0ahMs
Chapuis, C. (2006). The last equalisation from Freedive Central. Retrieved 25 May, 2018, from http://freedivecentral.com/a-the-last-equalisation-8610.html
donmoore. (2004). Learning Hands-Free Equalization in DeeperBlue Forums. Retrieved 11 August, 2017, from https://forums.deeperblue.com/threads/btv-hands-free-dry-tips-and-techniques-please.78528/
Kay, E. (2000). Prevention of middle ear barotrauma. Retrieved 11 August, 2017, from https://staff.washington.edu/ekay/MEbaro.html
Laminar. (2008). BTV (Hands Free) dry tips and techniques please in DeeperBlue Forums. Retrieved 11 August, 2017, from https://forums.deeperblue.com/threads/btv-hands-free-dry-tips-and-techniques-please.78528/
Mana, F. (2011). Equalization for freediving. Milano, IT: Magenes.
Nick F. (2015). Hands-free equalization? from Norcal Underwater Hunters Forum. Retrieved 11 August, 2017, from http://norcalunderwaterhunters.com/forum/index.php?topic=8386.0
Roydhouse, N. (1993). Underwater ear & nose care. Flagstaff, AZ: Best Publishing Company.
Stern, A. (2018). Hands free equalisation – How to equalise without pinching your nose – VTO and BTV equalisation. Retrieved 31 May, 2018, from https://www.youtube.com/watch?v=osGPbM78STc
unirdna. (2003). Hands-Free Equalization in the DeeperBlue Forums. Retrieved 11 August, 2017, from https://forums.deeperblue.com/threads/hands-free-equalization.33787/
Zuccari, A. (2016). La Compensazione Hands Free. Retrieved 24 May, 2018, from http://www.youtube.com/watch?v=xO4Kh7qtgrE