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.

ScubaLab took 21 scuba masks into the water to test field of view, volume, function and features. Here's the rundown.

A twin-lens mask with a special skirt, the Synergy combines soft, high-grade silicone with a tapered design. It balances support and flexibility to provide a perfect fit for almost any face.

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Designed for free-diving and spearfishing, the Nano mask uses Cressi's new Integrated Frame Design in which the two-piece frame is recessed into the mask's skirt. The dual-lens mask is made to fit very close to the face, allowing divers to move through the water and maneuver in tight spaces with minimal hydro drag.

The MP206 Chameleon mask from IST Sports is made from a liquid-injected, hypoallergenic silicone that is soft and supple, resulting in a skirt that offers comfort as well as a watertight fit. Its raked inverted-teardrop dual-lens design delivers a wide field of view. To enhance the underwater view, the mask is fitted with a new type of ultra clear lens that allows for increased light transmission.