Perhaps the oldest piece of true diving equipment is the mask. Like other scuba gear, its simple purpose is to allow our bodies to function in a liquid world. The mask's contribution to this adaptation is to provide an air space in front of our eyes so they can focus. Your nose must also be available to equalize the mask's volume and your head's natural air spaces. Simple functions to be sure, but finding the right mask for you can be a complex task centered around one overriding concern: proper fit. Here's a remarkable but true statement: a poorly fitting mask is the most common and significant problem of dive gear selection.
With so many masks to choose from, the process will be far easier if you can first narrow the field by defining your own needs and preferences. Do you want a clear or an opaque mask? Two lenses or three? Prescription or nonprescription? High- or low-volume? With purge or without? After you know the types of masks you're looking for, you're ready for a trip to your dive retailer to begin trying on available models.
Once at the store, the "sniff test" is not the place to begin. Do this first: Without using the strap and without inhaling, look straight up and gently place the mask on your face. It should rest comfortably and evenly, contouring to your face with no gaps. Have someone else also look for gaps. Now place a regulator mouthpiece in your mouth. While still looking up, there should be no gaps. Again, have someone else look for them.
Without using the strap, place the mask on your face while looking forward. Gently inhale a small amount. The mask should stay in place. A strong inhalation would close minor leaks and make it an invalid test. With your regulator mouthpiece in your mouth, repeat the sniff test, gently. Still no leaks? Still comfortable? Keep going. Using the strap, adjust for best fit. Check to see how easy the straps are to adjust when the mask is in place. If you normally dive with gloves and hood, try this adjustment with these items on.
The mask must fit without touching the tip of your nose, or being uncomfortable in the area between your nose and lip. With regulator in, again check the nose. With reg still in place, try using the nose pocket to equalize with one hand. It should be easy to do with one hand and not hurt your nose. If at all possible, try your best two or three dive masks in the pool or open water.
After following these steps, you should have a mask that fits, even if your face is hard to fit. To further improve fit and comfort, consider replacing the strap with a neoprene or similar strap.
