It’s your window to the underwater world!
The dive mask is a piece of kit that we depend on very much, without it, our venture into the deep virtually finishes at the surface. A dive mask provides us with an air space between our face and the water. This allows us to focus on objects underwater and provides us with a clear view. Although the basic purpose of a mask is very simple, it comes in all different sizes, colours, price-ranges and even as full face masks. Some high-tech masks can provide the diver with the actual dive data on a small display. So, how to choose a dive mask has some basic rules and factors, which should come into play before you make your choice.
What Size and Volume do you Need?
Size is an important factor which we need to consider. A close fit mask has a small volume, which means less air is required to clear the mask of water. A low volume mask is less buoyant, provides better trim and reduces the strain on your neck. A high volume mask requires more air to clear and is often a little buoyant while looking upwards.
With or Without a Purge Valve?
To clear a standard mask, it requires the diver to exhale through the nose, while pressing on the top frame of the mask and slowly looking upward. A mask with a purge valve allows the diver to exhale through his/her nose into the mask, thus opening a valve to drain out the water. The purge valve is placed at the bottom of the mask below the nose. The most common problem with the purge valve is sometimes leaks water into the mask.
Care must be taken that the nose has enough room inside the mask. The nose pocket should be easy to pinch, permitting the diver to block the nose and equalise the ears. It is crucial that divers who wear thick gloves or three-finger mitts can easily access the nose pocket.
Most masks on the market have lenses made out of tempered glass. This type of glass does not shatter under pressure. It is scratch resistant and has anti-fog characteristics, unlike that of plastic lenses. Some masks offer not only front lenses, but small panes on the side of the mask. This allows more light into the mask, increases peripheral vision and offers a more light-filled field of vision. The downside to these masks is the increase of volume and size. They are slightly heavier than single face pane masks.
Seals and Skirt Material
The days have gone when masks were made of rubber. Today, the modern mask skirt is made of silicon, flexible and less prone to ultraviolet light rays than rubber. Plastic skirts are not suitable as a dive mask; they become hard, offer a poor seal and discolour quickly. Silicon skirts are soft, flexible and mould well to the face, a benefit to a diver who requires a close fit, mask seal. Modern masks come in a variety of colours, the clear silicone skirt offers most light penetration into the field of vision. Some divers find black silicone masks very claustrophobic, due to lack of natural light.
These should be adjustable at both sides of the mask, to allow the length to be adjusted. The mask strap is there to keep the mask on the divers face, but should not be overly tight, this encourages the mask to leak. Remember to make allowances for wearing a hood. The strap should be easy to adjust, and the mechanism should lock securely into place.
If this is not the case, the mask strap may slip, and become increasingly longer during the diver. Many divers prefer to wear a ‘slap-strap’ over the actual mask strap, this helps to prevent hair entanglement and makes it easier to put on and take off.
Full Face Masks
These are great for cold water dives, compatible with communication systems and provide comfort and a huge field of vision. The full-face mask is easy to use, but requires training before use. They are more expensive than a standard half mask, but have the regulator already in place.
Masks and Technology
New designs are always available, in all different price classes. To consider is the mask that integrates a dive computer and a wireless pressure receiver. This provides a diver with crucial information such as depth, time, air pressure and decompression stops. The display for this information is found in a heads-up display. Such masks are fantastic for photographers who have both hands full, poor visibility conditions, night dives or for an adaptive diver who requires extra assistance. These masks come with a much higher price tag than the standard half mask.
Often divers who wear contact lenses or glasses have custom-made prescription lenses. Prescription lens masks really improve a diving experience and are comfortable for the diver to wear. Some divers use soft, day contact lenses and are happy with the experience. Here, the prescription lenses would make a massive difference to wearers of hard contact lenses, while hard contact lenses are not recommended on a dive.
Check the Mask Fit
The fit of the mask is of utmost importance; this is the factor that creates a watertight seal. In my opinion, you should fit a mask with a mouth-piece in your mouth. The mouth-piece ultimately changes the shape of our face, therefore skin folds and contours appear which were not there before. A good mask fit should be free from gaping holes, pressure points on your nose and forehead. It is best to try the mask without the mask strap, press it lightly onto your face and inhale. Check for a secure seal, no hair or foreign objects should obstruct the seal.
Care and Maintenance
Store it in a cool, dry place, preferably in its box away from other dive equipment. Do not leave it in direct sunlight, or in the car in the window. Wash and dry it thoroughly after each dive, store it in a box which prevents the skirt becoming deformed and prevents scratches on the glass or lenses.
Defogging a New Mask
Commercial defog is available to remove the protective, anti-scratch layer that is left on the inside of the mask after manufacturing. Saliva works just as well, but do not use any abrasive substance. Spit or place anti-fog onto the inside of the mask, rub it well with your thumb until it squeaks, rinse with water. Be aware of washing masks with camera housing O-rings and ports, some commercial defog may damage these items.