Equalisation Tips for Diving San Diego’s Deeper Reefs

The ability to equalise comfortably and consistently is the single most important technical skill for reaching San Diego’s productive deeper reef structure. Without it, you can’t safely access the 35–55 foot depths where large sheephead hold at Point Loma, where white seabass ambush from the mid-column at La Jolla, or where lingcod sit on the outer reef edges. Poor equalisation technique in San Diego freediving is the barrier between divers who plateau at 20 feet and those who unlock the full productive range of the local kelp and reef ecosystem.

The Physics of Equalisation: Why It Matters

Pressure increases by one atmosphere (14.7 psi) for every 33 feet of water depth. At 33 feet, the water exerts twice the pressure on your body as at the surface. This pressure acts equally on all air-filled cavities — your middle ears (connected to the outside world via the Eustachian tubes), your sinuses, and your lungs.

For the lungs, the pressure increase simply compresses the air — no equalisation needed. But the middle ears are enclosed: pressure from the outside (via your ear canal) can only be equalised by opening the Eustachian tubes and introducing air from behind the eardrum. Fail to do this and the pressure differential deflects the eardrum inward, causing pain (ear squeeze) and, if continued, rupture and barotrauma.

The Eustachian tubes are small, easily blocked by congestion, and must be actively opened. Different techniques use different muscle groups to achieve this.

Technique 1: Valsalva (Not for Freediving)

The Valsalva manoeuvre — pinching the nose and blowing — is familiar from air travel and common in SCUBA diving. For freediving, it has significant disadvantages:

• Uses diaphragm and abdominal muscles that compress the lungs — at depth with compressed lungs, Valsalva may simply not work
• Consumes significant oxygen
• Can cause inner ear barotrauma if performed too forcefully
• Inefficient for the rapid equalisations needed during a fast descent

Avoid Valsalva for freediving beyond recreational snorkelling depths. Transition to Frenzel as soon as possible.

Technique 2: Frenzel Equalisation (The Freediving Standard)

Frenzel equalisation uses tongue and throat muscles to pressurise the nasopharynx and push air through the Eustachian tubes, with the glottis (vocal cord area) closed. This isolates the equalisation action from the lungs entirely.

How to learn Frenzel:

1. Close your glottis by making a “K” or “G” sound and holding it — this locks your throat, isolating throat/tongue from lungs
2. Pinch your nose closed
3. Move your tongue upward and forward, as if making a “K” sound — this compresses the air in your nasopharynx
4. Feel the air push through your Eustachian tubes and the resulting click or pop in your ears

Practice sequence:

• Practise Frenzel dry on land until the mechanics feel natural
• Practise in a swimming pool at 5–10 feet, equalising on the descent
• Learn to equalise early and continuously during descent — every 3–5 feet
• Never descend past the point where equalisation becomes effortful or painful — stop and ascend a foot, then try again

Technique 3: Mouthfill (for Advanced Depths)

For advanced freedivers accessing San Diego reefs below 60 feet, the Mouthfill technique stores a reservoir of air in the mouth/throat before the dive, which is used for equalisations at depth where the compressed lungs can no longer supply equalisation air. This is beyond the scope of most spearfishing at local sites but relevant for divers pushing toward the 70–100 foot range.

Common Equalisation Problems at San Diego Reefs

Blocked Eustachian tubes: The most common issue. Can result from:

• Diving while congested (cold, allergy, sinus issue) — don’t dive if congested
• Pre-existing Eustachian tube dysfunction — consult an ENT specialist
• Cold water causing tube swelling — warm water through the ear canal before diving

Reverse squeeze on ascent: Occasionally, air trapped in the middle ear cannot escape on ascent, causing pain. If this happens, ascend slowly, tilt your head to the affected side, and try gentle Frenzel attempts.

Unequal equalisation (one ear problems): If one ear equalises well and the other doesn’t, there may be anatomy-specific dysfunction. An ENT evaluation is worthwhile — chronic one-sided equalisation difficulty can be treated.

Pre-Dive Equalisation Routine

Before entering the water at any San Diego site, run a dry pre-dive equalisation check:

1. Perform 3–4 Frenzel equalisations on land to confirm tubes are open and patent
2. If one or both sides feel blocked — don’t dive that day
3. Breathe steam or take a decongestant the night before if you frequently struggle with blocked tubes (avoid decongestants that might cause other issues)

Good equalisation technique is learnable by anyone with normal Eustachian tube anatomy. Practice it consistently and check the Element app conditions score before each San Diego session — diving on high-visibility, calm-swell days reduces the stress and hurry that make equalisation harder. Relaxed diving produces better equalisation.