What is the best equalisation technique for freediving?

Frenzel is the gold standard for recreational and competitive freediving. Unlike Valsalva (which requires lung pressure), Frenzel uses the tongue as a piston and works independently of lung volume — making it effective at deeper depths. Most AIDA courses teach Frenzel from AIDA 2 onwards.

At what depth does Valsalva stop working for freediving?

Valsalva becomes unreliable below 15–20m. At depth, the lungs compress and there isn't enough pressure differential to force air into the Eustachian tubes. Divers attempting to push Valsalva deeper risk a middle ear squeeze (barotrauma).

How long does it take to learn the Frenzel technique?

Most students achieve basic dry-land Frenzel within 1–4 weeks of daily 10-minute practice sessions. Getting it reliably underwater and on the descent typically takes 1–3 months of consistent pool or open-water practice.

What should I do if I can't equalise on descent?

Stop immediately, ascend 1–2 metres, re-equalise, then descend slowly. Never force through ear pain — this indicates the Eustachian tube is closed and forcing pressure will cause barotrauma. If you cannot equalise after two attempts, abort the dive.

Can I freedive with a cold or congestion?

No. Congestion blocks the Eustachian tubes, making equalisation impossible or unreliable. Freediving with congestion carries a high risk of middle ear squeeze, perforated eardrum, or sinus squeeze. Wait until fully clear before diving.

Technique Guide

Equalisation

The single most important skill in freediving — and the reason most beginners plateau. Valsalva, Frenzel, Mouthfill, and BTV compared. Plus a 5-step learning programme and interactive troubleshooter.

Technique Comparison

Technique	Depth limit	Learning curve	Used by
Valsalva	~15m	1–2 sessions	Scuba divers, beginners
Frenzel	~25–30m	2–8 weeks dry-land	AIDA 2+ freedivers
Mouthfill	40m+	3–12 months	AIDA 3+ and competitive freedivers
BTV (Hands-Free)	Unlimited	Years of practice	Competitive depth athletes

Valsalva

Up to ~15m · Easy to learn

Close mouth, pinch nose, blow gently. Lung pressure forces air through Eustachian tubes.

Limit: Fails when lungs compress too much (below ~15m). Risk of oval window damage if over-pressured.

Frenzel

Up to ~25–30m · Moderate

Pinch nose, close glottis, drive tongue upward (T/K motion). Tongue acts as a piston, independent of lung pressure.

Limit: Limited by air reservoir in mouth/pharynx. Runs out around 25–30m on a full breath.

Mouthfill

Up to 40m+ · Advanced

At 15–20m, transfer a full mouthful of air from lungs into the buccal cavity. Close glottis. Use that trapped air as the sole source for all deeper equalisations.

Limit: Requires good Frenzel first. Mouthfill capacity runs out around 50–60m for most divers.

BTV (Hands-Free)

Up to Unlimited · Very advanced

Voluntary opening of the Eustachian tube by muscle contraction alone — no nose-pinch, no hands. Used in no-limits and constant ballast competition.

Limit: Extremely rare ability — fewer than 5% of divers achieve reliable BTV.

5-Phase Frenzel Learning Programme

Follow these phases in order. Do not skip phases — each one builds the neurological pattern that the next phase relies on.

Discover your soft palate

Week 1–2

Sit comfortably. Inhale half a breath. Pinch your nose firmly. Try to blow very gently while keeping your mouth closed. Notice the air pressure build behind your nose — that's Valsalva. Now, without blowing from the lungs, try to say a silent 'K' sound. Feel the back of the tongue arch upward? That tongue movement, repeated while pinching the nose, is the start of Frenzel.

10 min/day

Isolate the tongue piston

Week 2–3

Using a nose clip (hands-free practice): take a half-breath, close your glottis (hold your breath mid-exhale — feel how the throat seals), then drive your tongue body upward with a 'T', 'K', or 'G' sound. You should feel clicks in your ears. No chest movement should occur. If your chest moves, you are using Valsalva, not Frenzel. Practice 50 reps.

10 min/day

FRC (half-breath) equalisation

Week 3–5

Exhale half your breath before practising — this simulates the lung volume at 10m. With reduced air in the lungs, Valsalva will fail (no lung pressure), but Frenzel should still work. Confirming equalisation at FRC on dry land is the key milestone before attempting it underwater.

5 min/day

Pool duck-dive at 2–3m

Week 5–8

In a pool, duck-dive to 2–3m using Frenzel only — no Valsalva backup. Equalise every 30 cm of descent. Return to the surface between each descent. Keep the glottis closed throughout. If anything feels sharp, return to the surface immediately.

Pool session 2×/week

Rope descent to 5m–10m

Month 2–3

Using a descent line in open water, descend feet-first to 5m then 10m, equalising every 30–50 cm before any pressure is felt. This trains the habitual, anticipatory equalisation pattern that protects ears on all dives going forward. When 10m is solid, Frenzel is established.

Open-water session 2×/week

When NOT to Dive

warning
Any ear pain on the previous dive — dive with pain only once, and you may dive with pain forever
warning
Cold, congestion, or allergies — swollen Eustachian tubes make equalization impossible and barotrauma near-certain
warning
After recent ear surgery or perforated eardrum — consult an ENT, not a dive instructor
warning
Feeling of fullness or pressure in the ears before you've even entered the water
warning
You've already failed to equalize twice on the same descent — the tube is swollen, rest is the only solution

Interactive Troubleshooter

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