The human eye cannot focus in water. The mask provides an air pocket so your eyes can focus and you can see clearly underwater.
Also known as: scuba mask, dive mask, diver's mask, goggles (improperly), half mask, face plate
Enclosed nose - Your nose must be within the eye pocket so you can adjust for pressure changes. This is why swim goggles cannot be used for scuba diving.
Tempered glass - Plastic fogs up and standard glass is hazardous if accidentally broken.
Desirable features (found in virtually all masks intended for scuba diving)
Feathered, double skirt - Makes mask seal more reliable and comfortable
Wide strap with touch buckle adjustment - Mask adjusts quickly, easily and stay adjusted during the dive
Canted-in bottom - Shapes eye panel for maximum viewing angle up and down and side to side.
Low volume - The smaller the mask, the less drag it has while diving. Your face may require something a bit larger, so don't consider this an absolute.
Purge valve - Use to blow water out (but you can do this easily without a valve)
Special lenses - Some masks can be fitted with prescription lenses, which is convenient if you wear glasses or use contacts.
How to choose a mask:
For most people, the problem in choosing a mask is deciding which one you like best rather than finding one you like. With the help of someone at your local PADI Dive Shop or Resort, choose several masks with the features you like.
- Hold the mask gently against your face. Do not use the strap.
- Inhale gently through your nose.
- If it fits, the mask will stick to your face and stay there without leaking and without continuous suction through your nose.
- Choose from the ones that fit
- Don't buy a cheap mask. They may look the same, but the things you can't see (quality of silicone, glass) as just as important as those you can. It is one of your most important pieces of gear. Think of it this way: If you only have a mask, you can still have a lot of fun swimming in the shallows looking at fish, shells and other stuff (kids do this all summer). If you have every piece of scuba gear except a mask, you wouldn't even get in the water.
- Scrub out the mask and use defog. Mask fog plagues beginning divers, but it's actually easy to prevent. First, scrub out a new mask with soft scrub, toothpaste or as recommended by the manufacturer. This removes a chemical that sometimes coats the glass during manufacturing and causes fog up. You only need to do this when you get the mask. Then, before each dive, use defogging solution according to the instructions. Your mask will stay fog-free.
- Be fashionable. You'll find there are lots of masks that fit you can choose from. That means you can find one that fits right, feels great, has the features you want and matches the rest of your gear.