mask fogging

Question
My wife and I are new the diving and we are currently getting our open water certification (just need to do our open water dives). We both have problems with our masks fogging and have tried several different antifog products. During our confined water dives our instructor pointed out that I am exhaling thru my nose more than the regulator. I also have trouble relaxing and taking slow deep breathes (I`m guessing because i exhale thru my nose and my mask floods and fogs up constantly). Can you help?

Answer
Hi Don,

It sounds like your instructor correctly identified your mask fogging problem.  Exhaling through your nose will definitely cause your mask to fog and it doesn't matter what type of antifog you're using.  The moisture in your exhaled breath is the source of the fog and constantly exhaling into the mask will simply overpower the antifog.

You and your wife can watch each other while underwater and if you see bubbles coming from the edge of the mask skirt when you exhale, then you are exhaling through your nose.  If you have a purge valve in your mask then you'll see bubbles coming from the valve if you are exhaling through your nose.  How to stop it can be problematic.  You have to find a way to seal the back of your throat using your soft palate so that air only travels through your mouth to your lungs and back.

A trick that I've used before is to have students blow up a balloon.  In order to do that, you have to exhale only through your mouth.  You can also exhale into an empty soda bottle.  In order to pressurize the bottle, you must exhale only through your mouth.  Now the trick is to transfer that maneuver to your snorkel and to your regulator.  The nice thing about these tricks is that you can practice them almost anywhere and you don't need water.  You can even hold your finger across your lips and then exhale against it and see if you can maintain pressure.

Don, as you've discovered, excessive exhalation through your nose will definitely cause some mask flooding.  Mask fogging and flooding will add to your stress level and make it very difficult to take the slow deep breaths recommended for diving.

Try the suggestions I've provided and see if they'll help you control your exhalation difficulties.  It'll take some practice but, with time, I think you'll be able to clear up your problem.

Best wishes for a fog-free dive!!

Mike Giles
Mike's Dive Center
mikescuba.com