Diving mask

The diving mask (also scuba mask or pressure equalization mask called ) is part of a diving equipment and belongs to the basic equipment ( NBC equipment ) of a diver. It consists of a body made ​​of soft rubber or silicon in the front view of a planar disc is inserted and the face of the diver has a soft sealing lips to prevent the ingress of water into the diving mask. The sealing lips are usually made of silicone, as this with the skin does not cause allergic reactions when touched. An adjustable elastic strap holds the diving mask on head.

In everyday language the diving mask is referred to as diving glasses or goggles. These designations are not useful, because unlike a spectacle encloses a mask and the nose.

The diving mask is to be distinguished in particular by the swimming goggles. The swimming goggles protects the eyes about chlorinated water. It differs from the diving mask by the smaller jars and the missing nose pocket, also by the simpler banding.

Construction

A diving mask is equipped with:

• A window made of tempered glass. Expensive glass panes of laminated glass (glass and plastic glued in layers ) are largely resistant to breakage. Plexiglas are indeed unbreakable, but scratch it easily.
• Can a nose pocket to depose through which the divers without diving mask hold your nose to equalize the pressure when diving (or blow into air can to prevent a vacuum ).
• A double sealing edge
• A split head band

Function

The diving mask allows the diver to see clearly underwater. The human eye is adapted to the refractive index of air. If the eye directly in contact with water, the eye lens can not compensate for the increased refractive index of the water - the diver then everything looks blurry.

The refractive index at the transition between the mask and water is 1.33 (4/3 ) and causes through the air before the eyes of an enlargement: objects appear 33% larger and distances 25% lower than they are in reality. For example, a three-meter- long object than four meters long (magnification by 33 %) and the distance of four meters will appear to the object than three meters (closer to 25%).

Eyeglass wearers usually use an immersion mask, alternatively contact lenses. The ground glass of the diving mask is less than the corresponding diopter glasses. This is caused by the greater refractive index of the water. The diver can therefore by an optical diving mask over water did not look very sharp.

Molding

There are various forms of diving masks:

• Regular masks have a central sight glass.
• Masks for apnea diving or underwater rugby have a low internal volume. Characterized the diver requires less air for the pressure equalization.
• Masks with split window: The often lower eye relief ensures a large field of view, the lower inner volume and partly better fit will be perceived as pleasant. They are (also ) for the insertion of optical glasses for eyeglass wearers. Today, optical lenses are glued from the inside to the windows of the mask.
• Panoramic Dive Masks have additional viewing panels on the sides and thus offer the diver an expanded field of view. They are also often used in underwater photography in order to better recognize the face of the subject.

• Full face masks are primarily used by professional divers and diving in cold or polluted water. Because here the regulator is directly attached to the mask, even radio while diving is possible. The masks often have special devices to equalize the pressure across the nose. Other arrangements, such as interior masks or purge, largely prevent fogging of the visor.
• Diving helmets are a special type of diving mask dar. Compared with full-face masks is partly lack of opportunity for direct pressure equalization through the nose to notice (or only with nose clip ). They offer similar full-face masks more protection, apart from a Plexiglas sphere helmets. Lightweight helmets be worn with neck collar, traditional helmets with shoulder piece.

Choosing the right dive mask

The tightness and thus the optimal fit of the mask can be tested as follows: Putting the mask on your face and breathe easily through your nose, the mask should keep on the face. The masking tape should not be too tight / solid, otherwise the mask body could be forgiven. The mask must fit comfortably and securely. Since each mask in the seat and the construction is different, can not be dispensed with such a simple and quick test to perform. This test should especially make women because they tend to have a narrower face.

Especially when scuba diving and deep diving when it is necessary to produce a pressure balance between the water pressure and the pressure inside the mask under water. This is ensured through breathing and the connection through the nose pocket and over the nose to the throat. By exhaling through the nose, it is also easier possible to fill the mask with air and leerzublasen. This is easier if the air volume is smaller in the mask.

For pressure compensation in the ears of the diver must breathe against a closed nose. The nose pocket should therefore also be optionally accessible when wearing thick neoprene gloves and allow cooperation pinching the nostrils.

Some models allow the replacement of the glasses. When changing prescription masks of this type thus have an advantage, because you have only buy new glasses and not a completely new mask.