Vandit Kalia, 11 February 2025.

In my Open Water classes, I talk about how safe a sport diving is and what a low injury rate it has compared to other sports.   However, 20+ years of being a dive professional and running a dive center has taught me one thing - most ear barotrauma incidents go unreported, and if these were factored in, the injury rate in diving would be much higher:  divers (especially those who are newly certified) hurting their ears is far, far more common than general scuba injury rates would lead us to assume. To set expectations and avoid making this post needlessly alarmist - let me be clear that most of these injuries are NOT serious, requiring hospitalisation or surgery or anything.    These injuries usually cause the diver some pain initially and fullness in the ears for a few days, before getting better.    Usually - but there is always a risk of the injury being more serious. Having looked at how equalisation is treaded by most agencies and how divers actually equalise in practice, it is obvious to me that this is one skill where there is a yawning chasm in terms of transferring the knowledge of how to actually equalise safely:  the devil lies in the details and these details are not communicated properly.     This article is intended to address that gap.

HOW EQUALISATION WORKS (AND WHAT HAPPENS WHEN IT DOESN'T)

This part should be familiar:  when you descent, the water pressure increases and transfers itself through your external ear canal to your ear drums, causing them to flex inwards due to a pressure imbalance between your outer and middle ear.   This initially is felt as pressure and, if ignored as you descent, increases to pain. The mechanism for equalising is forcing air from the Eustachian tube (a narrow tube extending from the back of the roof of your mouth) to your middle ear, causing the pressure in the middle ear to increase, till it matches the external pressure.  No pressure imbalance, no pain. So far so good? Now, here is what happens if you do NOT equalise: Initially, at a depth of as little as 1-1.5m, the ear drum bends inwards into the middle ear, as do these parts of your ear called the round window and oval window (which are very thin membranes).    As you keep descending, and the pressure imbalance goes up to 0.2 bar or so, the ear drum stretches further and its tissues begin to tear, causing an inflammation.   Small blood vessels may also rupture, causing bruising and even a bit of bleeding - some of this blood and mucus may actually get sucked into your middle ear and alleviate the pressure difference to some degree by reducing the air space.   This fluid in the middle ear is also what causes a feeling of fullness, which lasts for several days to a week usually, before it is reabsorbed in the body.      The inflammation and tearing of tissues can also cause your ears to be sensitive to pressure for several days till they heal. What if you go deeper without equalising?   There is the risk of ear-drum rupture - especially if you descent very quickly.   When that happens, the colder water in your middle ears affects your balance mechanism and can cause severe vertigo and dizziness, which reduces after a while as the water inside your middle ears (where it most definitely does NOT belong) warms up.     This, needless to say, is a significantly more serious injury: although it typically does result in a full recovery, it may make the eardrum more prone to damage in the future. But wait, there is more.      As you descent, the pressure differential can cause your Eustachian tubes to close.      And by then, your ears are probably hurting.     So what do most divers do?   They get a little frantic and try to equalise forcefully by blowing long and hard against pinched nostrils.   At some point, if they use enough force, it raises the fluid pressure in the inner ear, which can cause a rupture of the very thin membrane that makes up the round window.     This causes the fluid from your inner ear (cochlea) to drain into the middle ear.    This is painful, it results in temporary loss of hearing and if not treated, can result in permanent hearing loss.    We are talking serious barotrauma here.

WHEN TO EQUALIZE

The most common mistake divers, especially newer ones, make is they don't equalise often enough.   They are distracted by many other things and only remember to equalise when their ears remind them by hurting.    So here are some tips to avoid that: 1)  To start with, equalise early and often: the moment you feel pressure, equalise.       The first 5-8 meters are the most critical, as that is when the pressure change, as a percentage, is the highest.   Keep yourself vertical as you do so and descend slowly:  if you find yourself falling backwards, butt first, while descending, lean forwards a little (and work on your descending skills). 2).  Equalise gently - not forcefully.   If you are unable to equalise, don't get impatient and force it.    Repeat the attempts to equalise gently:  try more often, instead of trying harder.      Unless you have a congestion or some other issue, it may take a minute or two but eventually it will work - and in the event it doesn't, that dive was not meant to be. 3) If your ears are hurting, it is too late to equalise.  If you are try to equalise at this point, you will need a lot of force and that can cause various degrees of barotrauma.   What you need to do is ascend a little bit - enough so that the pain recedes to mere pressure.    Equalise here.    It is also important to not ascend any higher, especially if you already have equalised earlier - go up to high and your ears pop the other way, which makes equalisation harder.    So it is important to ascend just enough that the pain reduces to gentle pressure, and equalise there. Needless to say, being able to descend (and ascend) in a controlled manner, especially in the blue and without a reference line, is a very important skill in ensuring safe equalisation.   If you are not able to do this, a pool is a great place to practice:   learning to control your depth in the first 3-4 meters, and you can control it anywhere.

HOW TO EQUALIZE

There are several techniques for equalisation: Valsalva:  Pinch your nose and gentle blow through the nose Frenzel:   Close the back of your throat, pinch your nose and make the sound of the letter "K" Toynbee:  With your nose pinched, swallow Lowry:  Pinch your nose and both blow and swallow at the same time Voluntary Tubal Opening:   Tense the muscles of the throat and the back of your mouth and push the jaw forwards and down, which tenses the muscles along the side of your jaw. Of these, the Valsalva is the easiest and most common technique used by divers, and works well enough if you do it often and early, but also the one that is most prone to causing injuries if done incorrectly.   It is worth practicing the other methods and seeing if you can make it work - and the best thing is that you can do it anywhere, anytime (although maybe avoid it on date night?). That said, if the Valsalva is the one that works best for you, don't sweat it.    That's what most people do, and it works well if done correctly.      And hopefully, this article has taught you how to do it correctly.