Diving face masks are crucial to the well being of the
sport. It is most important that the mask fits properly. There are several
points to look for when purchasing a face mask:
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To make sure the seal against the face is correct, one should look straight
up, put the mask on the face with the strap out of the way, let go of the
mask with the hands, and then suck in through
the nose. If the mask is drawn to the face, and can be held there temporarily
by suction, then it fits!
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Moustaches commonly interfere with the fit. If they are bushy and there is
no skin above them under the nose, air will leak through the hair and cause
the mask to leak. Some divers shave the extreme upper part of the moustache.
It makes one look more like Clark Gable! Some apply silicone grease to the
hair. Some shave the entire thing off.
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Once the mask fits properly determined by the method described above, then
it is necessary to determine whether the size is correct. It would be hard
to get a mask that is too large to fit. If you do use a mask that is too
large, the strap would have to be so tight it would cause the mask to leave
a red ring around the face. It is easy to get a mask that is too small to
fit. If the mask is too small the side vision will be reduced. You want to
get a mask that allows you to see the most from side to side. And, don't
count those side plates found on some masks. When you look through a side
plate under water the distortion is so great things seen are not where they
really are.
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Another thing to look for is the volume of the mask. Low volume masks are
ones that get your eyes close to the glass. High volume masks have a lot
of room in them. For the most part low volume masks offer the greatest vision
from side to side. They are easier to clear of water. But, if you have a
large face you may have to use a higher volume mask.
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There are two places masks may caused irritation. The bridge of the nose
and the skin directly under the nose. When you try on a mask be sure it does
not hit the bridge of the nose (too low a volume), and does not feel the
least bit uncomfortable under the nose. A little discomfort in the store
will grow to a large pain after an hour of skin or scuba diving.
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Buy silicone, not rubber. The material will last almost indefinitely. Rubber
is rotted by oil. The oil on a diver's face will cause the mask to be useless
after a few seasons. Also, the clear silicone masks allow more light to penetrate
leading to less tunnel vision.
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There are two disadvantages with silicone:
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1. Silicone will absorb colors from objects touching it. For example, if
you attach a rubber snorkel or snorkel keeper to the silicone strap of the
mask, the black color will slowly be absorbed into the strap making it look
permanently soiled.
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2. If mold begins to grow on any silicone material it will embed itself in
the material. Even if the mold is killed, the remnants of it may permanently
stain the silicone making it very unsightly. Deep-Six has soaked silicone
mouthpieces in pure Clorox for days. The mold has been killed but the unsightly
color still remained. The mouthpiece was sanitary but it sure didn't look
that way!
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Before the first dive with a new mask it may have to be cleaned of a
film left from the manufacturing process that will cause fogging problems
underwater. The only way Deep-Six knows to remove this film is with a toothbrush
and toothpaste. A vigorous brushing right after purchase is recommended.
Don't confuse this first fogging problem with the usual fogging that divers
experience on every dive unless they coat the lense with an anti-fogging
compound or spit (that is lightly rinsed off) just prior to the dive. One
of the better anti-fogging compounds consists of a solution of 50% rubbing
alcohol and 50% baby shampoo. The alcohol cleans the lens and the baby shampoo
leaves a film that keeps the fog from forming. Baby shampoo will not sting
the eyes.
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Forget buying a mask with a small purge valve. They are hard to use and may
cut down on the vision.
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There are masks that allow the introduction of prescription lenses for a
very reasonable cost.
The principal behind keeping a mask from fogging up during
the dive is to get a thin coating of a material to cover the lens without
distorting the vision. Spit, shampoo, raw potato juice, commercial anti-fogging
products, etc. have a slimy material that will leave a thin layer on the
glass. If the diver coats the lens with one of these materials, and gives
the mask a light rinse fog should not form as long as the mask does not dry
out. It won't underwater, but it will if you coat the lens and then put the
mask down while doing something else. The best thing to do is coat the lens
last, put the mask on the face, and enter the water. Then let a little water
in from the lake or ocean, slosh it around, and then dump it out. All this
should be done with the mask on the face. The principle behind fogging is:
When a diver breathes out into the mask the moist air hits the cooler glass
and little droplets of water form on the lens. This is the fog. If the glass
were coated the droplets would just go into the coating and spread out instead
of forming a droplet that interferes with vision.
Be gentle with mask straps. They can and do break when
pulled too hard. It's best to put the mask on the face first and then pull
the strap down behind the head but not so low it hits the ears.
Because light has to travel through water, the mask glass,
and the air inside the mask before it enters your eye it creates a magnification
at close distances (1-15') underwater. Things can appear 1/3 larger and 1/3
closer than they really are. This creates problems for the underwater
photographer, spearfisherman, etc. What you thought was a legal catch may
get you into trouble when the true fish size becomes apparent after surfacing.
It you want to see this effect, put one eye underwater and look at one of
your fins that is partially sticking out of the water. Underwater the fin
will look larger and closer!
Clearing a mask of water while underwater is a very important
skill. It may sound easy to come to the surface if you get water in your
mask just to dump it out. Surfacing from a dive takes time and is inconvenient
to you and your buddy especially if it is for a problem that could be easily
corrected underwater. So, mask-clearing underwater is a major component of
any scuba course. It is a simple process, especially if you are able to breathe
underwater. The best method is to place the hand lightly on the top of the
mask (this keeps the air from escaping), look straight ahead, and then blow
gently through the nose. The water should leave through the bottom of the
mask because the trapped air pushes it out. If it does not all go out on
the first try, inhale more air and do it again. The position of the head
during this is very important. If you look down too far the water will stay
against the glass. If you look up to much water will get in the nose when
the air is not coming out. Some divers find it easier to open the bottom
of the mask slightly WHILE AIR IS COMING OUT OF THE NOSE. This allows the
water to exit without having to build up pressure in the mask.
Since the mask fits so closely to the face and makes
a seal, there is the possibility it will be squeezed against the face when
the diver descends. After all it is an air space that is going to be crushed
to 1/2 its size at 33 feet. If the diver does nothing about this mask squeeze
dire consequences may result. The mask is at lower pressure than the pressure
inside the diver's body. The excess molecules under the skin will push the
skin into the mask. The eyeballs will bulge into the interior of the mask.
The pressure inside the skin of the nose becomes greater than the pressure
in the nostrils. Divers have come up with a face that looks like it's been
battered. In fact, the problem looks worse than it really is. The nose may
bleed, the eyes may have blood vessels break so the whites will turn red,
and the skin may look like someone slapped the hell out of it. All of this
may be avoided by simply putting a little air in the mask through the nose
as you descend in the water. Although it would be more hydrodynamic, divers
cannot wear goggles while diving because there is no way of pressurizing
the inside of them?
Professional masks for diving are made of glass, not
plastic. Glass is hard to scratch. The glass should be tempered. Usually
the word, "Tempered" is found on the top of the glass. Tempered means the
glass will break in very little pieces rather than in large sharp shards.
I have seen a diver fall head first into the ocean off a dock and hit the
mask head on. The mask shattered but the diver was not cut (fortunately).
Diving into the water with the mask on, dropping the mask in a shower, or
packing it tightly in a suitcase may cause it to shatter and become worthless.
Placing one hand over the glass lens of the mask when doing an entry is advised.
Lastly, when you store a mask it is important to not
have pressure against it. If you were to pack a mask under a weight, for
example, the mask may retain the shape it has been forced into for a prolonged
period of time. That is why mask boxes are a wise investment.
