Masks and Snorkels

Masks

To see clearly underwater, the diver needs a diving mask. A typical mask will consist of four main parts:

• the frame:
  This secures the body to the lens.
• the strap:
  This is either a split or single rubber strap which holds the mask against the wearer's face. The length of the strap is adjusted by buckles.
• the lens:
  This must be scratch and shatter resistant and is usually made from tempered glass. Avoid plastic, which tends to stratch and fog easily.
• the body:
  This is usually made from a soft rubber compound to form a waterproof seal against the diver's face. It encloses the eyes and nose and allows the wearer to pinch their nose in order to clear their ears whilst submerged. Drain valves may be fitted to aid mask-clearing, but these are unnecessary.

Many different types and styles of mask are available. Take advice from an experienced diver of instructor. People who have eyesight problems should have corrected lenses fitted to their masks. It is also possible to wear contact lenses with an ordinary mask.

Silicon rubber is often used for the body of the mask. This material is non-allergenic to body tissue and very long lasting. Since face seals differ in shape, you should select a mask which will seal against your face and yet be comfortable. Test a new mask for correct fit by putting it on your face without the strap and inhaling. A correctly fitting mask will stay in place until you exhale through your nose. Look for a mask with a good angle of vision, both vertically and horizontally.

Avoid full face masks and/or masks which have attached snorkels.

Snorkels

A snorkel allows the user to breathe whilst lying on the surface with their face in the water. This makes finning on the surface much easier than having to continually lift one's head in order to breathe. It also permits observation of the underwater scene from the surface.

In its simplest form, the snorkel consists of two parts: a soft rubber mouthpiece which is gripped by the teeth and forms a seal under the lips, and a rigid or semi-rigid tube which points upwards over the submerged head. The top of this tube is open and allows the user to draw in air without inhaling water.

The most common shape for the snorkel is a simple J or L, although there are various curved shapes available. A typical length will be 40 to 45cms. If the tube is too long, it will require too much effort to clear it of water, too short and the water may splash in the end.