Activities The Great Outdoors What You Need to Know About Scuba Masks Share PINTEREST Email Print Yusuke Murata / Getty Images The Great Outdoors Scuba Diving & Snorkeling Gear Skills Safety Hiking Climbing Skiing Snowboarding Surfing Paddling Fishing Sailing Learn More By Natalie Gibb Natalie Gibb owns a dive shop in Mexico and is a PADI-certified open water scuba instructor and TDI-certified full cave diving instructor. our editorial process Natalie Gibb Updated May 17, 2018 What do a clownfish, a shipwreck, and an eagle ray all have in common? You can see them all through a scuba mask -- your window to a beautiful underwater world. One of the most important pieces of diving gear, a mask must be equalized, defogged, and fit properly. In other words, there is more to scuba masks than meets the eye. What Is a Scuba Mask? Scuba masks are different from other kinds of masks. Created specifically for scuba diving, they are made of high-quality materials like tempered glass and silicon, materials tough enough to withstand the underwater environment. Snorkeling masks and other masks designed for surface water sports may be made of inferior materials, such as plastic lenses that can fog and scratch easily. Such weak materials could break during a dive. Although scuba masks may work well for snorkeling and other water sports, masks created for surface water sports generally do not work well for diving. Divers Can't See Underwater Without a Scuba Mask A mask helps to keep water out of a diver's nose, which is nice. However, the primary purpose of a scuba mask is to allow a diver to clearly focus his eyes. A diver can breathe and swim underwater without a mask (student divers practice this in a scuba certification course). However, he can not see well enough to read a pressure gauge or clearly distinguish hand signals without one. Swim Goggles Can't Be Used for Scuba Diving A scuba mask must enclose a diver's nose. This feature increases a diver's comfort by allowing him to empty water from a leaky mask and preventing him from getting water up his nose. However, the reason it is absolutely essential that a mask covers a diver's nose is that it enables the diver to equalize the air pressure in the scuba mask as he descends. This prevents the mask from painfully suctioning on to the diver's face, and in an extreme case, sucking his eyeballs out. A Mask Is a Mask, Right? This is actually not true. Many different styles of scuba masks are available to recreational divers. Purge valves, optical lenses, and side windows may be useful or annoying to a diver. It is important to understand the different kinds of scuba masks and to have a clear idea of what type of mask you want before making a purchase. Not All Scuba Masks Fit All People Many new divers do not realize that scuba masks need to be fit. People have different head and face shapes, so it makes sense that fit is important. No matter what the price or aesthetic value of a mask, do not buy a mask if it does not fit correctly. An improperly fitting mask can leak or press uncomfortably on a diver's face. For this reason, it is important to determine a mask's fit before purchasing. All Scuba Masks Fog Up, but There Are Ways to Prevent Fogging Experienced divers know that a foggy scuba mask can ruin a dive. Not only does a foggy mask block a diver's view of their incredible surroundings, but it impedes communication and can be disorienting. All masks will fog up if not treated correctly, but any foggy mask can be fixed.