Freediving Equalization: The Complete Guide

Freediving Equalization: The Complete Guide

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Freediving equalization is the skill that decides how deep you go — long before your lungs or your breath-hold ever become the limit. Most new spearfishers turn back not because they run out of air, but because their ears hurt. The good news: equalizing is a learnable technique, not a gift, and this guide walks through how your ears behave under pressure, the techniques from Valsalva to mouthfill, how to fix the problems that stop you, and how to train the whole thing on dry land.

Equalization sits alongside breath-hold and relaxation as one of the three core freediving skills. If breath-hold is about doing more with the air you have — covered in our guide to holding your breath longer for spearfishing — equalization is about getting your body safely down through the pressure to use it.

How Pressure Affects Your Ears Underwater

Water is heavy. Every 10 metres of depth adds another atmosphere of pressure, and that pressure squeezes the air spaces in your body — most importantly the air behind your eardrums in the middle ear. As you descend, the outside water pressure pushes your eardrum inward. Left unchecked, that stretch goes from a feeling of fullness, to discomfort, to genuine pain, and eventually to injury (barotrauma).

The fix is simple in principle: you add air to the middle ear to balance the rising pressure. That air travels up the Eustachian tubes, the narrow channels connecting the back of your throat to each middle ear. Equalizing is nothing more than actively pushing a little air up those tubes so the pressure on both sides of the eardrum stays equal. The reason it feels hard is that those tubes don't open on their own under pressure — you have to open them deliberately, and the deeper you go, the less spare air you have to do it with.

Your ears aren't the only air space that feels the squeeze. Your mask is an air pocket pressed against your face, and it needs equalizing too — a small exhale through the nose every few metres keeps it from clamping down and bruising the skin around your eyes (a "mask squeeze"). Your sinuses equalize passively for most people, but they're the reason congestion causes such trouble. The middle ear is simply the air space that complains first and loudest, which is why equalization is almost always discussed in terms of your ears.

Safety Warning Never push through ear pain. Pain is the signal that your eardrum is already stretched past its safe range — forcing deeper risks a ruptured eardrum or middle-ear barotrauma that can end your season. If an ear won't clear, stop the descent and come up.

Equalize Early, Often, and Gently

The single biggest habit that separates divers who equalize easily from those who struggle is timing. You equalize before you feel pressure, not in response to it. Start at the surface, give a gentle equalization as you take your last breath, and then equalize every metre or so on the way down — small, frequent, gentle pushes rather than one big forceful effort.

Why gentle? Because once your eardrum is already pushed inward, the Eustachian tube tends to lock shut, and a hard, late shove (typical of Valsalva) can damage the very tube you're trying to open. Head position matters too: keeping your chin slightly tucked or neutral opens the tubes more easily than tilting your head back to look down at the bottom.

"The dive isn't deep until your ears say so. The day I started equalizing on the surface — before I even left it — the bottom stopped fighting me." — Fishes One Hook, dive log #103

The Equalization Techniques, From Valsalva to Mouthfill

There are three techniques worth knowing, and they form a ladder you climb as you go deeper. Each pushes air up the Eustachian tubes a different way, and each has a depth where it stops working.

TechniqueHow it worksBest depth rangeRisk
ValsalvaPush air with the diaphragm against a pinched noseSurface to shallowHigh — fails and can injure at depth
FrenzelUse the tongue as a piston to push trapped air upShallow to deepLow — efficient and controllable
MouthfillHold a reservoir of air in the mouth to Frenzel fromDeep (past residual volume)Advanced — needs training

Most beginners start on Valsalva because it's intuitive, but it's a dead end for depth. The technique that actually carries you down is the Frenzel, and the difference is worth understanding in full — we break it down in Frenzel vs Valsalva: which to use and when.

The Frenzel Technique: Your Workhorse

The Frenzel technique is the equalization method nearly every competent freediver and spearfisher relies on. Instead of driving air up from your chest, you trap a small pocket of air in your mouth and throat, close off your throat and soft palate, and use your tongue like a piston to compress that pocket and force air up the Eustachian tubes. It's efficient, it works at depth where Valsalva can't, and it doesn't waste your precious lung air.

It also feels alien at first, because it uses muscles you don't consciously control day to day — the glottis, the soft palate, and the back of the tongue. Learning to isolate them is most of the battle. Our full walkthrough, the Frenzel technique step by step, covers finding those muscles and running the movement, and you can rehearse the whole thing dry before you ever get in the water.

Freediving Equalization
Equalize on the line before discomfort arrives — small, gentle pushes every metre.

When You Can't Equalize: Common Problems

Almost every diver hits an equalization wall at some point, and the cause is usually one of a handful of things: congestion from a cold or allergies, one stubborn ear that lags behind the other, poor head position, or a reverse block where air gets trapped on the way back up. The fixes are specific to the cause, and pushing harder is almost never the answer.

If you regularly stall at the same shallow depth, or one ear simply won't cooperate, work through the causes and fixes in why you can't equalize (and how to fix it) before you blame your technique. Diving with any head congestion is a common, avoidable mistake — it narrows the tubes and is a leading cause of ear barotrauma.

Training Your Equalization on Dry Land

Here's the part beginners miss: the best place to learn to equalize is on your sofa, not at 8 metres. Every part of the Frenzel can be isolated and rehearsed dry, with no pressure and no risk — finding your soft palate, locating your glottis, and feeling air move up to your ears. Divers who train dry arrive in the water already knowing the movement; they just have to apply it.

A short daily routine builds the muscle control faster than occasional in-water attempts ever will. We lay out a full progression of drills in equalization exercises you can do on dry land — start there before your next session.

Pro Tip Practise the Frenzel dry, sitting upright, with no nose clip first. If you can feel your ears "click" or fill while seated, you've found the movement — now it's just a matter of repeating it head-down underwater.

Going Deeper: Mouthfill and Hands-Free

Once the Frenzel is solid, two more skills open up. The mouthfill technique lets you keep equalizing past the depth where your lungs are too compressed to supply more air — essential for deep freediving but firmly an advanced skill. And some divers develop hands-free equalization (BTV), opening the Eustachian tubes with throat muscles alone, no nose-pinch required.

You don't need either to spearfish productively. Most spearfishing happens in the shallow-to-mid range where a clean Frenzel is plenty, and improving relaxation pays off as much as any technique — our breath-hold tables guide covers the CO₂ tolerance and calm that make equalizing easier too. Build the ladder one rung at a time: gentle Valsalva to learn the feeling, Frenzel as your workhorse, and the advanced skills only once the basics are automatic.

Frequently Asked Questions

Frequently asked
What is equalization in freediving?
Equalization is actively adding air to the air spaces in your ears (and mask) to balance the rising water pressure as you descend. You push a little air up the Eustachian tubes so the pressure on both sides of the eardrum stays equal, preventing pain and injury.
Why can't I equalize my ears when freediving?
The most common causes are congestion from a cold or allergies, equalizing too late and too forcefully, poor head position, or relying on Valsalva at depth. Diving congested is a leading cause; if one ear won't clear, stop and ascend rather than forcing it.
Should I use Valsalva or Frenzel for freediving?
Valsalva is fine for learning the feeling in the shallows, but the Frenzel technique is the workhorse for freediving because it works at depth and doesn't waste lung air. Most divers should learn the Frenzel as early as possible.
How often should I equalize on the way down?
Equalize early and often — give a gentle equalization at the surface and then roughly every metre on descent, before you feel any pressure. Frequent, gentle pushes are far safer and more effective than one hard, late effort.
Can I practise equalizing without going in the water?
Yes — and you should. The Frenzel technique can be fully rehearsed on dry land, sitting upright, which lets you learn the muscle control with no pressure and no risk. Daily dry drills are the fastest way to improve.
Contributor

Lucas Davis

A Fishes One Hook contributor — logging dives, testing gear, and writing it all down between surface intervals.

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