There is nothing more frustrating than struggling to enjoy yourself with a fogged mask underwater.  Most mask fogging is caused by warm humid air inside the mask meeting a lens surface cooled by water.  Warmer air is capable of holding more water vapor than cooler air.  Therefore, when air is cooled, a portion of its water vapor condenses into tiny liquid droplets, or “fog”.  Defog solutions prevent fogging by creating a thin, invisible film on the lens which creates a “sheeting effect” eliminating the formation of condensation droplets.

However, most defogs don’t work effectively on a new mask because of silicone leeched from the mask skirt and other factory residues left on the lens during the manufacturing process.  The lens on most new masks needs to be pre-cleaned with a mild abrasive to allow the defog to effectively change the surface tension of the tempered glass lens.  pr4

Sea Buff is the most effective pre-cleaner that I have come across.  Soft Scrub works pretty good, but has bleach in it, so your mask has a strong smell that is hard to get out.  More abrasive cleaners are likely to scratch the lens and less abrasive just don’t get the coating off.  I have seen people use a lighter to burn the coating off, but this is dangerous and a great way to ruin  a $100 mask before you even get it wet.  A bottle of Sea Buff  is $5.00 and will clean several masks.  Bonus use for the remainder of the bottle…it is a great slate cleaner, too!

Tips to diving fog free: Pre-clean new masks, follow the directions on your defog, store your mask in a hard case to protect it from dirt, salt and contaminants, put it away dry to prevent mold and algae build-up, avoid leaving your mask in the sun or on your head prior to a dive-the heat will cause a spike in the mask’s temperature which contributes to fogging, don’t exhale thru your nose-which increases the temperature on the inside of the mask.

Invest a few minutes to take care of your mask and it will reward you with clear dives.