Passive Flooding of Paranasal Sinuses and Middle Ears as a Method of Equalisation in Extreme Breath-Hold Diving
Authors: Peter Germonpré, Costantino Balestra, Patrick Musimu
DOI / Source: https://doi.org/10.1136/bjsm.2010.043679
Date: 19 October 2010
Reading level: Intermediate
Why This Matters for Freedivers
Equalising costs air and effort. This case report describes an extreme (and very unusual) workaround: replacing air in the sinuses and middle ear with water so you don’t need repeated equalisation manoeuvres on the way down. Even if you never use this technique, it’s useful because it highlights what really limits deep dives (air management, relaxation, and barotrauma risk) and why “clever equalisation strategies” can change performance and risk.
Synopsis
In deep breath-hold diving, equalisation is a constant tax: as you descend, the air spaces in your sinuses and middle ears shrink, and you normally have to push air into them repeatedly (Frenzel/Valsalva/Toynbee) to avoid painful barotrauma. The deeper you go, the more air you may need to “spend” on equalisation—air that then isn’t available in the lungs.
This case report describes a freediver who trained himself to do something that sounds almost impossible: he allows water to passively enter and fill his sinuses and middle ears during descent, instead of repeatedly adding air. The diver (a 36-year-old physical therapist) started with conventional equalisation for a few years, then gradually trained “passive equalisation” by keeping the nostrils open and letting water move into the nasal cavity, sinus openings, and Eustachian tubes as pressure increases. Over time, he found this became so natural that switching back to conventional equalisation felt difficult.
The authors couldn’t scan him during a dive, but they tested whether he could actually flood these spaces without forceful injection or major reflex reactions. Using MRI before and after he poured water into each nostril and moved his head into different positions, they showed clear water filling not only the maxillary/ethmoid/sphenoid sinuses, but also the middle-ear cavity and mastoid recess—without sneezing, coughing, pain, or discomfort during the procedure.
The diver then used this technique in extreme “no-limits” diving, reportedly reaching 209 m on a single breath (after progressively deeper dives over a few days). The proposed advantages are: - Saves air: less need to move lung air into the head spaces, potentially helping deeper dives. - Saves effort and oxygen: fewer active equalisation manoeuvres and a more relaxed descent. - Smooth descent speed: not “interrupting” the descent to equalise may reduce early hypoxia.
But the authors also highlight major risks and unknowns: - Infection risk: open water contains pathogens, and water can remain in sinuses for hours after the dive. - Middle-ear tissue effects: repeated water exposure might irritate/alter mucosa over time (they did not find abnormalities in this diver at the time of evaluation). - Training barrier: most people get strong discomfort/reflexes when water enters these areas; this diver adapted over years.
Bottom line: this is a fascinating, extreme case showing that passive flooding can be possible for at least one diver, and it reframes equalisation as not just a technique issue—but an air-management and physiology issue at the limits of depth.
Abstract
Breath-hold divers must equalise the paranasal sinuses and middle-ear cavities during descent to avoid barotrauma, but this requires using precious air that could otherwise remain in the lungs. The authors describe a diver who trained himself to allow passive flooding of the sinuses and middle ear with water during descent by suppressing protective reflexes. MRI performed before and after nasal water instillation demonstrated water within multiple sinuses as well as the middle-ear cavity and mastoid recess. Using this technique, the diver completed a series of extreme breath-hold dives and reportedly descended to 209 m on one breath. Potential advantages and risks (including infection and mucosal effects) are discussed.