Prevent Snorkel Mask Fogging
The Solution

You can prevent snorkel mask fogging; it is not difficult to stop, and it is important for enjoyment. Because how many times have you found yourself snorkeling along and realized you were cranking your head to the side to try and see out of the one spot on your snorkel mask that wasn't foggy? What a pain.

Well, it does not have to be that way. If you do things right you should rarely have any fogging in your mask, just crystal clear vision.

You may be surprised to learn that the number one reason for a foggy mask is a dirty mask. The moisture forming inside your mask has to attach to something. That something is dirt specks and oils. Moisture cannot easily attach on a very clean mask. With a clean mask the moisture sheets down and collects at the bottom instead of fogging.

Moisture also can attach to the microscopic imperfections in the glass. That is why anti-fog, baby shampoo or spit works. They act as surfactants that reduce the surface tension of the condensing water, making it less likely to cling to the glass.

Note: Our suggestions come from hands-on experience. We hope you find them helpful. You can help us if you purchase from the links below. We may make a small commission, from Amazon or other companies, at no extra cost to you. Thank you.

Prevent Snorkel Mask Fogging in Four Steps

Clean your mask often, and then don’t touch it inside. Clean it with toothpaste (paste, not gel), and a toothbrush, not your finger (because of oils). Use a small amount of toothpaste, and scrub the glass with it. Rinse it completely in hot water. Do this often. And with a new mask do this numerous times before your first use. We always have a travel-sized toothpaste tube in our snorkel bag with a dedicated toothbrush when we travel. (If your lens is not glass, use dish soap and a very soft brush or wash cloth so you don't scratch the plastic.)
Use anti-fog every time you snorkel. The cheapest and easiest is a very mild solution of baby shampoo and water. We use 15-18 drops of baby shampoo mixed with water in a 2.5 ounce spray bottle. Spray it in your mask and swish it around thoroughly so it touches every surface of the glass. We do not rub it around with our fingers because our mask is already clean from the step above, and fingers are oily. Then rinse your mask ONCE quickly with either fresh or salt water.
Then, put it on your face quickly. Shake out any water drops before putting it on. Try to have a relatively dry face. Once the mask is on with a good seal, try to keep from removing it and allowing moisture to enter. Try not to clear the mask by breathing inside of it unless you must (that adds moisture). We enter the water with a dry mask, over a dry face, and do not take that mask off at all during the snorkel, if possible. And it works.
If all else fails and you are out on the water with a foggy mask, remove it, spit in it, shake the mask around to coat the glass (try not to rub it with your fingers), rinse and dump it out, and put it back on. This will generally fix the problem. If you don't have a lot of spit, dilute it with a small amount of salt water to coat the glass. Spit is actually one of the best anti-fog solutions.

Nothing Works?
You May Need to Burn Your Mask

No, we do not mean you give up hope and throw your mask into a fire. New masks sometimes come with a layer of silicone grease on the inside of the glass. That silicone attracts water vapor, causing fogging, and may not be easy to clean off. So if the steps above do not work for you, and you have a tempered glass mask (don't try this with a plastic mask), then you may need to have your mask burned for you at a dive shop to prevent snorkel mask fogging. This is a process where someone uses a lighter or matches to burn away any coatings of silicone. You can see it being done in the video below. Obviously lots can go wrong doing this, like breaking your mask because of too much heat, burning your silicone skirt or yourself, so let a pro do it.

Anti-Fog Products

We use a simple solution of mild shampoo and water to prevent snorkel mask fogging.

But Stream2Sea now makes a reef-friendly Mask Defog that we will test in the future and report about in our newsletter. Stream2Sea is the same great company that makes the best snorkeling sunscreen that is reef-friendly that we use.

Also available is Gear Aid Sea Gold but follow their instructions carefully. That is not a product you use before each time you get in the water, and you do not want to get any of it in your eyes. JAWS Quick Spit Anti Fog is another product that is biodegradable, and is both a cleaner and anti-fog.

What About Full Face Mask Fogging?

One of the marketing features of a full face mask is that it stops fogging, because air flow is directed across the lens of the mask as you breathe in. Well, we have found that every full face mask we have used can still fog up. They still need to be cleaned to help prevent this problem, but more carefully, because they nearly all have plastic lenses, instead of glass. And if the plastic gets scratched inside it will increase fogging problems.

Why & When Does Condensation Form?
Learn to Avoid Temperature Changes

One final important tip to prevent snorkel mask fogging. Condensation happens when the temperature of the glass is lower than the air inside the mask. Basically that happens when you go from a hot environment to a cold environment. So when you have had your face in the water, and then come up and face the sun, the hothouse effect warms the air inside, and then when you plunge it back into the colder water the glass will quickly cool, and condensation will form. So when you are sitting up in the water to talk with your partner, or when you first put your mask on, make a habit of turning your back to the sun.

It Works!

We have shared how to prevent snorkel mask fogging for years in our eBook snorkeling guides. And many people have told us that by following these steps they have noticed a big improvement in stopping foggy snorkel mask problems.