Mask Fitting
How many times have you gone into a dive store, tried a mask
that seemed to fit just great, got on an airplane to halfway around
the world, jumped into the water and the mask leaked? There seems
to be a nearly universal way to try a mask, which unfortunately
happens to be the wrong way. Put the mask on, inhale through your
nose and guess what? The mask fits. Right? Wrong!
The big mistake is that no one dives or snorkels with a vacuum
in their mask or shouldn't be if they are. By inhaling through
the nose, an unnatural seal is created. Some divers have tried
on masks that don't even come close to fitting but as soon as
they inhale, a tight seal is created. While diving though, they
are not constantly trying to inhale through their nose (which
is what the store clerk told them to do) and now the mask leaks.
Someone told a tale of a dive store that displays all masks
without straps. The idea apparently is to check that a really
good vacuum makes a really good fit. Once again, no one dives
trying to inhale through their nose constantly and without a strap
no less.
Almost all modern masks have an outer seal and a narrower
inner seal. This inside seal covers everywhere except just under
the nose. If both of these seals touch the face than the odds
of that mask fitting and not leaking are very good. This is done
by putting the mask on with the strap loose, but in place, and
then tightening it to what would be normal if you were diving.
Some divers who have had very bad masks are in the habit of over
tightening the strap on a new mask in hopes of a better seal.
Don't do that especially while trying masks for fit.
The next step takes a second person or a mirror. Look around
the entire inside of the mask checking to see that the inner seal
touches everywhere. It is very important not to inhale through
the nose which forces the mask seals to touch if they didn't naturally.
Next check the outside seal the same way.
If the inner seal is not touching the face, especially next
to the side of the eyes, it is likely the mask won't work well.
But do check everywhere around the inside. The outer seal might
keep water from dripping in but not as well as if both seals touch.
Make sure the seals do not cut across any hairline or eyebrows.
Also that the side seals are not right at the edge of the eye.
One other problem can occur when someone laughs, smiles or
even squints. This motion creates lines or wrinkles next to the
nose. Sometimes this makes a passage where water pours in. Almost
every mask will leak when this happens. So don't laugh! Occasionally,
depending on the person, these wrinkles may remain even after
they stop laughing. In this case it may be necessary to straighten
the face by pulling down or sideways on the cheeks. Again this
is not necessarily a mask problem. So don't run out and buy a
new mask.
If absolutely necessary, to keep everyone happy, you can now
inhale slightly to check any unseen leaks. Sometimes a mask leaks
around the glass. This is very unusual and is a one off problem,
not the design of the mask. You can check this by holding the
mask with the face plate parallel to the floor and putting water
in the mask. If the face plate seal is faulty, drops of water
will appear on the outside.
Don't be fooled by the size of a mask's frame and lenses.
This has little if anything to do with how a masks fits. People
will look for what seems like a narrow or wide mask, depending,
but what counts is the size of the skirt where your face is actually
touching the mask. An exaggerated example but if the lens of a
mask is 1 foot wide but the skirt is only 4 inches, this would
fit a rather narrow face but the mask looks huge.
With literally 10's of dozens of masks on the market, there
is one that will fit. It may take awhile to find but it is out
there.