Defog a Diving Mask

It's bound to happen sooner or later: mask fog. Fog is an annoyance and source of frustration for a great many new divers - especially so with new equipment. You can prevent fog from forming by preparing the mask before diving. Taking the time to clean your mask before your next dive will make it a lot more enjoyable!

Steps

  1. Wash your mask in warm soapy water to remove the manufacturer's preservative lubricant. Masks today are made with silicon skirts. Silicon can change color and lose flexibility over time from exposure to the elements. Manufacturers coat the masks with a lubricant to protect this from happening while on the display racks at retail stores. It is this lubricant that is the culprit behind fog in new masks.
  2. Scour the inside of the lens with a mild abrasive cleaner. [Glass lenses only! Some masks have plastic lenses that will be scratched with this technique.] Soapy water will cut the grease for the most part, but the lens must be thoroughly cleaned in order to prevent fogging. Toothpaste is the best thing to use for cleaning the inside of the lens. Toothpaste needs to be NON GEL type the gel pastes do not contain enough abrasives. Household cleaners can work, but care must be taken to be sure that the mask is completely rinsed before use because household cleaners can irritate or injure unwary divers if allowed to remain in the mask. With circular motion and a little bit of pressure, thoroughly scour the inner surface of the lens with about a dime-sized drop of toothpaste for several minutes. Rinse and repeat 2-4 times.
  3. Clean the inside surface and rinse before entering the water on the day of diving. If the mask is removed for any reason, either spit (some say beware of this as there are a lot of nasties in saliva that you don't want in your eyes) on the lenses or add commercial defogging drops to keep them clean.



Tips

  • If your mask fogs often during your dive it is usually because you are breathing out a little through you nose. Your body temperature is 98.6 and the water temperature is usually much lower than that. This air coming from your lungs being warmer creates condensation after only a few small breaths. Kind of like your car window when the air is warmer on the inside than on the outside.
  • A common and cheap technique for keeping a mask clear that is used more regularly is to spit into it and rub the spit in all directions on the inside of the lenses (up and down, left to right). With the spit only give the mask a quick rinse (in and out once), give it a little swing with the hand to remove the drops and put the mask on. It will stay fog-free while you're diving. Best of all, you don't have to buy a commercial mask defogger or you might not have that at hand.
  • If you have followed these steps and still have trouble with mask fog, ask an instructor or dive master for tips on how they keep their masks from fogging up. An alternative is to burn the lubricant on the lens away with a common lighter (only glass lenses). Move the flame a bit, so the silicon edges around don't get damaged. Ask someone that did this before, like the shop owner where you are going to buy the mask (let them do it first and then pay). If some soot forms, don't worry. You can wash that away easily.
  • Don't allow your mask to dry out between dives on days of multiple dives. Drying them out leaves deposits of grit and minerals that allow fog to form more easily.
  • A lot of instructors would now disagree with the above. Human saliva contains over 550 types of bacteria. Over time masks that are spit in tend to grow a black mold around the lens. Commercial defoggers are far from expensive (usually $6-8 a bottle that lasts years on average) and tend to last longer during a dive. Apply a small drop to the lens and smear it around the lens - then rinse off. Voila! A fog free lens without feeling like you're wearing a science experiment!
  • If your mask fogs underwater, flood and clear it just like you learned in your open water course. Consider that flooding the mask probably makes it steam up easier too. So, you might have to repeat it after you did it once.
    If it's steaming up every minute, leave just a bit of water in and once in a while look downward while moving your head from side to side. The water under your nose might not be the most comfortable thing, but it's either that or aborting the dive.
  • A mild shampoo (baby shampoo to be precise) is an excellent defogger. Put 1 to 3 drops on the lens and smear it lightly and evenly over the surface, paying attention to the seals. Rinse thoroughly just before you enter the water, if not you might make bubbles on the inside of your mask instead. Works every time! You can also buy a small travel sized spray bottle and put in a few drops of baby shampoo and fill with filtered water. Rub it around and gently rinse with water, gently enough to leave a slight film on the inside of the lens.

Warnings

  • If household cleaners are used to scour the lenses initially, it is extremely important that the mask be thoroughly rinsed before diving. Household cleaners can irritate the eyes and skin and in extreme cases, may cause loss of sight. You're better off using toothpaste.
  • Use only light pressure. You don't want to scratch the lenses.
  • Only scour the lenses once. After you've removed the manufacturing goop, it is unlikely that you'll get more on the lenses.
  • Avoid using mint-flavored toothpaste; this will irritate your eyes as well.
  • Beware of using spit - there are a lot of bugs in saliva that you don't want in your eyes.

Related Articles

  • Scuba Dive in Cancun