Why do freedivers sometimes wear nose clips?
When freedivers are training or competing in a swimming pool, nose-clips are often used in conjunction with goggles to stop water penetrating the nose and sinus cavities. It’s a comfortable and in the case of sinus cavities, healthier way to train or compete.
In the ocean freedivers wearing no mask/goggles, or with water-filled goggles use a nose-clip, not only to keep the water out of the nose and sinus cavities but also to provide pressure to equalise the ears. It is much easier to perform a dive if the freediver is not constantly reaching to pinch his nose for equalisation.
The nose-clips freedivers use are different than the ones sometimes worn by swimmers. Why is that?
Swimmer’s nose-clips are used to keep water out of the nose on the surface where there is little water pressure. As a freediver dives deeper the water pressure increases. At approximately 10 metres the water pressure is double the atmosphere pressure at sea level, increasing with further depth. This necessitates the need for a more robust and infallible solution. Furthermore, one of the purposes of the nose-clip is to supply the necessary back pressure to allow the freediver to equalise. Instead of pinching the nose with his fingers the nose-clip completely seals the nostrils.
There is one more feature the nose-clip must have. In competitive freediving the freediver must be able to easily remove the nose-clip. Removing facial equipment like mask or goggles and nose-clip is part of the required surface protocol for the completion of a dive. The surface protocol is timed and must be completed with no mistakes in 15 seconds.
Freediving nose-clips are designed for a very stable securing of the airway, and ease of removal.