HOW TO BUY A MASK
Your mask affects the enjoyment and comfort of your diving probably more than any other single piece of equipment. Whether youíre buying your first one or trading in the one youíve been using, selecting the right mask is a very important decision.
FIT AND COMFORT - Youíve probably heard the phrase before, but what does it actually mean?
"Fit" is pretty easy - a mask that fits well forms an airtight (aka watertight) seal on your face. Check for this by placing the mask on your face (without using the strap to secure it to your head) and GENTLY inhale through your nose. Remove your hands. A well-fitting mask stays in place. The easier you can inhale to hold the mask in place, the better the fit.
"Comfort" is more subjective. A mask can fit well on your face but still not be comfortable. The most common complaint is rubbing against the bridge of your nose. Basically, a comfortable mask wonít feel like itís making contact with your face anywhere except around the seal of the mask skirt.
SILICONE CHOICES - Just about every popular mask sold today is made of some form of silicone. Different companies use different grades of silicone so youíll notice a difference as youíre switching between manufacturers. While most masks come in a "clear" silicone (actually opaque), some also come in black. Hunters and photographers might prefer a black silicone mask because it helps maintain mental focus for the former, and keeps out stray light for the latter. Other people prefer the clear silicone because thereís less of a "closed-in" feeling since you can detect movement and light through the clear silicone.
MASK VOLUME - Mask are commonly referred to as "high" or "low" volume. A high-volume mask is usually bigger, but also a bit heavier than a low-volume version. The high-volume mask can tolerate a bit more leaking (since it takes longer to fill up) but will also require a bit more clearing effort. A low-volume mask, because it sits closer to your face, usually will provide you will a bit more peripheral vision. Either one is a good choice as long as they meet your fit and comfort requirements.
HOW MANY WINDOWS - Masks generally come in one, two, three, or four-window versions. One-window masks (also know as "single vision") have a single pane of tempered glass, and offer a fairly good field-of-view and average peripheral vision. Two-window masks are have two lenses in the front of the mask, joined by a nosepiece. Three-window masks consist of a single front pane (like the one-window) and two side windows. Four-window masks consist of two windows in the front and two windows on the sides.
All masks with side windows offer the advantage of increased peripheral vision. But be aware that when an object moves in view from the side window to the front, thereís an optical "jump" (due to refraction) that some people find distracting. Others consider that a small tradeoff for the improved peripheral vision.
GLASSES & CONTACTS - If, like me, your vision is less than 20/20, you need to give some thought to how youíll correct your vision while underwater.
If you wear contacts, youíve already got the problem solved. I personally have worn both gas-permeable and soft contacts for almost 20 years now without any problems. The big advantage of wearing your contacts is that when you take your mask off, you can still see clearly. The disadvantage is the possibility of losing a lens. (Although with the proliferation of soft, disposable, daily-wear lenses nowadays, losing a lens is much less of a crisis than it was some years back.)
If you wear glasses, youíve got two choices - drop-in lenses or custom-ground ones. Either one can provide you with clear underwater vision.
"Drop-in" lenses are available in varying diopters and many stores carry them in stock or can order them for you. You simply chose your mask, pop out the lenses that came with the mask and "drop in" the new, corrective lenses. The advantages are that theyíre cheaper ($50-75) than custom-ground, they can be done at the same time you purchase the mask, and you donít need to have a glasses prescription to buy them. The disadvantages are that you canít correct for astigmatism, the pupillary distance (the distance between your eyes) is fixed, and drop-in lenses are not available for single-window masks.
"Custom-ground" lenses are made by an optometrist working in conjunction with your dive shop, and are ground to your exact vision needs. Corrections can be made for astigmatism. The pupillary distance will be exact. You can even have the lenses made as bifocals if you need them. And, because these lenses are bonded to the inside of a mask, you can choose any mask that fits your face, including single-window ones. The disadvantages are time and money as custom-ground will be a bit more expensive than drop-ins (generally running around $100 and up, in addition to the cost of the mask), will take 7-10 working days to be completed, and you must provide a vision prescription to order them.
FINDING THE RIGHT MASK - Now that you know all the things to look for, youíve got to actually find the mask thatís right for you. Hereís a step-by-step method:
1. Go to your local dive shop.
2. Try on every mask in the place.
3. Play close attention to how the mask seals.
4. Set aside the ones that fit.
5. From that group, try them on again, paying close attention to comfort, eliminate half.
6. From the remaining half, try them on again, pick the one thatís most comfortable.
7. Wear the mask, with the strap in place, for 3-5 minutes in the store. (Youíll look silly but a mask thatís not comfortable for a few minutes in the store wonít be comfortable in the water.)
8. Tell the salesperson what color you want and have them ring it up.
AVOIDING PROBLEMS - Sometimes masks that seem to fit in the store donít fit as well in the water. Since we use these masks with either snorkels or regulators in our mouths, it means our mouth is partially open and our laugh lines - major sources of mask leaks - come into play. So as you narrow down your choices in the store, try the mask with a snorkel in your mouth.
The other problem people create for themselves is over-tightening the mask. Tightening the mask strap can make the problem worse, not better. The way to tell if youíve got your mask strap too tight is to look at your face in a mirror after a dive. If the mask leaves a ring around your face, itís probably too tight. Ideally with a well-fitting mask, the water pressure should be enough to hold the mask in place. The strap does very little of the work.
We generally go diving to see spectacular sights underwater. A mask that provides good vision and fits well is a piece of equipment thatís worth itís weight in gold. Take time to find the right one for you.