Equalisation issues

Overcoming common equalisation issues with students on their Stage A course

As many of our students never freedive before or have arrived from a Scuba background some may find equalising challenging – especially in a head down position.

A bit of Physiology:ear

The eustachian tube is a 4cm long tube which leads from the middle ear to the back of the nasopharynx. While the roof of the tube is stiff the bottom is flexible and is usually closed. When performing pressurisation air is pushed through this tube (opening it momentarily) resulting in an equalisation.

The opening of the tube is controlled by two muscles – Tensor Veli-palatini and the Lavatory veli-palatini. Those muscles connect to the sides of the soft palette.

The soft palette controls wether air can flow between the lungs and the nose.

In order to perform an equalisation a few things need to happen:

  • The Soft palette needs to be in either the natural or bottom position to allow air to flow between the mouth (or lungs) and the nose.
  • The tube must be opened (even for a split second) to allow air to flow through it.

Limiting factors

As Scuba divers usually equalise with their head in the upright position and the rate of descent being slow many newcomers to freediving discover they have difficulties equalising with their head down. This is mainly because of on or more of the following:

Timing issues – As the rate of descent is much faster in freediving many divers delay their equalisation until they feel strong pressure or pain before attempting to compensate.

Technique – The valsalva manœuvre is not as effective as the frenzel. this especially applies for deeper dives. Not performing the technique correctly or not creating enough pressure is also a common issue.

Head position – Looking up (towards the bottom) has an adverse effect on streamlining but also makes equalisation a lot more difficult as it mechanically narrows the tube.

Physiological limitation – Some divers (in fact most) have one side which is narrower that the other. This causes one ear to equalise faster than the other.

Gravity – Once inverted, the weight of the tissue actually collapses the eustachian tube making equalisation more difficult.


The first step we must take in order to avoid eq issues is to make sure our student are aware of the different techniques and the most important consideration such as early and frequent equalisation, mastery of the frenzel technique, proper head position and timing and descent speed.

Providing the student can equalise on land with his /her head up we will follow the following procedure:

  • Test to determine if the student can equalise with their head down on land – sitting in a chair or on their knees ask them to drop their head between their knees until it is lower than horizontal. If they can equalise move to the water.
    • If they cannot equalise – focus on mastery of the frenzel and of creating constant pressure. Try to maintain pressure as they drop the head down in between their knees.
    • If this does not work focus on the spot where eq fails and try to push it beyond horizontal. Add jaw thrust and / or head tilt.
  •  Once equalisation works on land move to the water. Make sure the line is weighted enough to support FIM and follow the following sequence:
    • Head up FIM with first equalisation on the surface.
    • Horizontal FIM
    • Head down FIM
    • Head down CWT once FIM works effectively.

Only move to the next step once the student masters the previous step. Depth is not important – instead work on relaxation as it is a major limiting factor in equalisation.

Good luck and feel free to contact me with questions,




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