In apnea’s deep diving, the diver must master the pressure equalization. In contrast to apnea divers, scuba divers have the advantage of being able to vary their descent and ascent rate almost as freely as possible during a dive. They carry enough air. If you are experiencing problems with the equalization due to the increased environmental pressure, you can slow down or reverse the descent. After you have adapted to the increased ambient pressure, you can continue your dive.
Apnea divers do not have an unlimited air supply. If they have problems with the descent, this usually results in aborting the dive. In addition, the dive speed is significantly higher. When the diver is going down, it’s done with the head down. Pressing air from lungs into tubes is harder than with head up. All this is why it is extremely important for Apnea to master pressure equalization. In the following, I would like to introduce the most common pressure equalization methods.
It is common to all methods of equalization that the higher the pressure differential between the external pressure (water) and the internal pressure (the ear tubes / inner ear / frontal sinuses) is, the more difficult the compensation is. Therefore pressure equalization must be carried out at an early stage. The first pressure compensation may already be performed on the surface. You can dive with minimal overpressure in ear tubes. During the first 10 meters the pressure compensation must be carried out much more frequently. From the surface to 10 meters of water depth the air volume is compressed to half. At 20 meters the air volume is compressed to one third. The volume difference is less from 10 to 20 meters – and decreases continuously.
The most well-known method of pressure equalization is the Vasalva maneuver. In doing so, the nose is closed and air is pressed from the lungs into the pharynx and ear tubes. The advantage is that the pressure compensation is easy to learn. The disadvantage is that especially beginners do not dose the pressure and do too hard. Consequences could be a barotrauma.
An advanced method of pressure compensation is the Frenzel maneuver. The air is pressed from the lungs into the ear tubes, with the tongue base. The advantage is that the air can be displaced more finely. In addition, the pressure compensation can be performed almost continuously. You can check if you are doing Frenzel by trying pressure compensation with open mouth. When you succeed, you are doing Frenzel. If not, you are doing Vasalva.
Frenzel Mouth Fill
At depths where no air can be pressed from the lungs into the pharynx and ear tubes, the Mouth Fill is used. In this case, air is already displaced from the lungs into the throat space or jaws at lower depths (around 25 meters or less). In depth, air can now be pressed into the ear tubes similar to the Frenzel maneuver, but now air is not drawn from the lung, but from the mouth, and in doing so, the jaw muscles are contracted. The advantage is that this also works in depths beyond 30 meters.
Few divers master the Delonca maneuver. Here the ear tubes can be kept open. This can be practiced. Try to activate the muscles that are used exactly in the moment when the ears open when yawning.
A video will follow soon, explaining the methods …