The primary goal of a good mask is to optimize your field of view, both horizontally and vertically. You should also have a good downward view as well. Think about it, downward is where you will find your gauges, buckles, BC pockets, and just about anything else you will want to grab. The better your downward view, the easier it is to access and see your gear.
Low Volume
These are nice scuba diving masks because they require less breath to clear. When cruising through the water column, they will create less drag as well. They also tend to provide a larger field of view because the front lens is closer to your eyes.
Buckle/Strap Systems
Most of the time, buckles are easy to operate and they make strap adjustments easy. Others are just a pain to use. The buckle system on most of the modern masks today mount on the skirt rather than on the frame. This gives you a whole variety of advantages, which include improving the range of motion for positioning the strap as well as enabling the buckles to be folded flat against the lens for packing or storing.
Skirts
All mask skirts are made from silicone, but there is a variance in thickness and suppleness when it comes to each mask. Others will butt against your face with stiff edges that seem to dig into your skin. Some manufacturers will add different surface textures in the area of the cheeks and forehead to increase comfort and improve the seal. Some of the top skirt designs to consider are High Seal, LiquidSkin, and TruFit.
Skirts will also come in black and yellow coloring, typically. Clear skirts will maximize the amount of light they allow in the mask. This is an advantage when diving in the shadowed or green water. However, if there is a white sand bottom, this can cause a blinding reflection. Black skirts may seem a little more claustrophobic, but they are great at blocking reflective light, which is why they are loved by underwater photographers.
Purge Valves
If you can’t get a mask to seal, consider a model with a purge valve. These are mounted at the bottom of the nose pocket and is designed to keep water from building up inside of a leaky mask. The best valves will drain without any effort. At worse, you may have to gently blow through your nose to get it going.
It may not seem like an important piece of scuba diving gear, but your mask is important.
If you have more questions, just contact Sharky Scuba in Ottawa.