The Anatomy of a Mask

When the sport of snorkeling was in its infancy, it came as no surprise that the gear selection was extremely limited. As more people joined the world of snorkeling, they brought with them a plethora of facial sizes and body types that did not fit the equipment of the day. The manufacturers of the equipment took notice and began to research and introduce a wider variety of sizes and designs that would better accommodate the diverse snorkeling population. You, as a snorkeler, are now able to select gear that addresses your personal individuality. In an effort to help you, the consumer, become a more educated shopper, we have written quite a number of articles for that purpose. The intent of these articles, is to further educate you with regard to the materials used in the manufacture of the various items used. (If history interests you, read our Evolution of the Mask article)

This article includes educational material, diagrams and videos to help you understand and will help you make the right purchase. The mask, when broken down to its most basic components, consists of the lens or lenses, the skirt, strap, frame or no frame, adjustment buckles and strap keepers. The photo, left is the Deep See Clarity which also offers diopter lenses.


The lens for most masks are made using tempered glass or plastics. Tempered glass has a wide variety of applications and are used in car and truck windows, glass doors and tables and it is also used in the making of bullet proof glass. The preference of tempered glass is due to its strength as well as the fact that when it does break, it does so in small fragments rather than in sharp shards, it is a "toughened" glass. It is accomplished by using controlled thermal or chemical treatments during the processing. These processes create balanced internal stresses which give the glass its strength. Tempered glass does have a slight green tint to it which is caused by iron content but there has been a trend in the past couple of years of manufacturers offering ultra clear lenses. These lenses virtually eliminate the slight greenish hue. The video on the right goes into more detail on lenses.


The skirt may be made from quite a few different materials, silicone, natural rubber, PVC, silflex, crystal silicone are just a few of the materials used. Back in the day (pre 1975) skirts and straps were made using natural rubber. While inexpensive, natural rubber did have its drawbacks. The life span of rubber was not very long as being exposed to the natural elements caused the skirt to dry out and crack. Chemicals used in swimming pools also served to shorten the life and as an avid snorkeler, you could almost always count on having to purchase a new mask every year. While we do not sell natural rubber skirts, the material is still being made, so be careful with what you purchase especially on the internet. To learn more on what the lenses are made of, watch our video to the right.


The introduction of silicone (post 1975) brought with it, a skirt that not only had a better tolerance to the elements, it also allowed light to penetrate which reduced the sense of tunnel vision associated with the black or natural rubber masks. Silicone was more expensive to produce so using it were significantly more expensive than those made using natural rubber. Two things should be noted with respect to silicone, the first being that silicone will begin to develop a yellow tint over time. This yellowing is due to exposure to the oxygen in the air and while it makes the skirt less attractive, it does not affect the elasticity of the skirt. The second is that silicone that comes into contact with black rubber for prolonged periods can also take on a black hue at the points of contact. There are definite benefits for choosing silicone over other materials, some of which include a more consistent elasticity in a wider range of water temperatures and is great for those with rubber allergies. The video on the left gives more details on skirt materials.


PolyVinyl Chloride or PVC is a plastic material that is used in some skirts. Masks using this material for the skirting are usually significantly less expensive than those using natural rubber or silicone because PVC is cheaper to produce. But it is not without its drawbacks, the elasticity is greatly reduced in cooler water temperatures causing it to stiffen up. This does affect the skirt's ability to conform to the face which is a problem with the seal and will cause major leaking. So be careful when you purchase on the internet since you can not touch and feel, if it does not state silicone skirt, you can guarantee it is PVC.

Silflex and other similarly named materials combine silicone with other materials and generally perform to varying degrees between silicone and PVC. Crystal silicone is the clearest of silicone which is due to the liquid injection process used to create the skirt.


Straps are used to hold the masks to the face and are usually made using the same materials as the skirt but there are a couple of exceptions. One of these exceptions is the neoprene strap and the reason for using the neoprene is mainly to lessen hair entanglement. The strap is attached by weaving it through the buckles or you can purchase the neoprene strap wrapper separately and velcro over the silicone strap. The Deep See Strap Wrapper can do this.

Another important feature to the strap is the materials used is the buckles which can either be metal, plastic or a combination of the two materials. The important part of the buckle is a roll bar and it looks very much like a watch pin. The roll bars serve to make threading the strap a lot easier. Roll bars can be made of metal or a heavy duty plastic. Just an FYI, if yours pops out, find it as it is not replaceable. Also what is used are commonly called strap keepers and the purpose for the strap keeper is to keep the mask adjustment consistent. All strap keepers are made of plastic or neoprene materials.


The frame serves to bring together the basic elements and we find lighter weight plastics and are also seeing what are called Frameless. Compared to the heavy metals of yesteryear the plastics of today make them quite comfortable on the user's face. They do away with the frame all together by bonding the the skirt directly to the lens or lenses.