Optimizing your field of view, both horizontally and vertically, is the primary goal of a good mask. But having a good downward view is of particular importance. After all, downward is where you’ll find your gauges, buckles, D-rings, BC pockets, weight ditch handles and just about everything else you’re going to want to grab. The better your downward view, the easier it is to see and to access your gear.

Some buckles are easy to operate and make strap adjustment a dream. Others are simply a pain in the ass. The buckle systems on most modern masks mount on the skirt rather than the frame. This offers a number of advantages, including improving the range of motion for strap positioning, and enabling the buckles to be folded flat against the lens for stowage or packing.

All mask skirts are made out of silicone, but the thickness and suppleness varies from mask to mask. Some skirts mold to your face like a second skin, creating a comfortable, watertight seal. Others seem to just butt up against your face, with stiff edges that dig into your skin. Some manufacturers add different surface textures in the forehead and cheek areas to further increase comfort and improve the seal. LiquidSkin, TruFit and High Seal are among the top skirt designs worth investigating.

Skirts also come in clear and black, typically. Clear skirts maximize the amount of available light they allow into the mask. This can be a real plus when diving in shadowed or green water. However, when diving in bright tropical waters over a white sand bottom, all that reflective light streaming through a clear skirt can be blinding. Black skirts, while a bit more claustrophobic, are great at blocking this reflective light, which is why underwater photographers love them.

It may not seem like a crucial piece of life-support gear for scuba diving, but your dive mask is important. Need help finding a well-made mask that's perfect for you? ScubaLab explains five features you should understand when shopping for your next window on the underwater world.

Field of View

Optimizing your field of view, both horizontally and vertically, is the primary goal of a good mask. But having a good downward view is of particular importance. After all, downward is where you’ll find your gauges, buckles, D-rings, BC pockets, weight ditch handles and just about everything else you’re going to want to grab. The better your downward view, the easier it is to see and to access your gear.

Low Volume

Low volume masks are nice because they require less breath to clear. They also create less drag when cruising through the water column, and they tend to provide a wider field of view because the front lenses sit closer to your eyes.

Buckle/Strap Systems

Some buckles are easy to operate and make strap adjustment a dream. Others are simply a pain in the ass. The buckle systems on most modern masks mount on the skirt rather than the frame. This offers a number of advantages, including improving the range of motion for strap positioning, and enabling the buckles to be folded flat against the lens for stowage or packing.

Skirts

All mask skirts are made out of silicone, but the thickness and suppleness varies from mask to mask. Some skirts mold to your face like a second skin, creating a comfortable, watertight seal. Others seem to just butt up against your face, with stiff edges that dig into your skin. Some manufacturers add different surface textures in the forehead and cheek areas to further increase comfort and improve the seal. LiquidSkin, TruFit and High Seal are among the top skirt designs worth investigating.

Skirts also come in clear and black, typically. Clear skirts maximize the amount of available light they allow into the mask. This can be a real plus when diving in shadowed or green water. However, when diving in bright tropical waters over a white sand bottom, all that reflective light streaming through a clear skirt can be blinding. Black skirts, while a bit more claustrophobic, are great at blocking this reflective light, which is why underwater photographers love them.

Purge Valves

For divers who just can’t get a mask to seal, buying a model with a purge valve might be the only solution. Mounted in the bottom of the nose pocket, a purge valve is designed to keep water from building up inside a leaky mask. The best purge valves will drain without any effort; at worse all you have to do is blow gently through your nose to get it going.

Ready to buy a mask? See ScubaLab's 2013 mask-testing results, including the Testers' Choices for single-, dual- and multiple-lens categories.