A mask is the most important item in your snorkel set. When you go snorkelling, it is generally to enjoy all the underwater sights. However, it is very difficult to do this if your snorkel mask keeps fogging up. Anyone who has ever used a snorkel mask knows what I am talking about. Lucky for you, there are a couple methods to prevent fog from building up inside your mask.
New Snorkeling Masks
All new snorkel masks come with a residue on the inside of the lens that is left over from the manufacturing process. No matter how much you attempt to defog the mask, fog will always build up because of this residue. Here are a couple ways to remove it.
Toothpaste is actually a very good way to remove this residue. Just squirt some toothpaste onto the inside of your snorkel mask and rub it around with your finger or a very soft cloth. Don’t do this with all the fancy versions of toothpaste. The classic kind works best. Also, don’t use a rough cloth as it could scratch the inside of your mask. If you are so inclined, you can leave the toothpaste in overnight. This leaves enough time for the chemicals to properly react.
This method requires you to burn the residue off the mask. What you want to do is run the tip of a flame over the inside of the lens until they turn black. Once every inch of the lens is black, wait for it to cool down, then wipe the soot away with a cloth. Repeat this until it is difficult to get the glass to turn black. Be careful to avoid heating up the plastic inside the mask. Also, please do not do this if your lenses are plastic. It will melt them and you would have destroyed a perfectly good snorkel mask. Personally, I don’t recommend this method. There are too many risks and toothpaste works just fine.
Used Snorkel Masks
Simply removing the residue will not completely prevent your snorkeling mask from fogging up. Before every dive, you will have to treat the inside of it with some defogging agents.
Spit on the inside of your mask and rub it around. Give it a quick dunk in fresh water. The goal is to leave a thin layer of saliva on the inside of the mask. This prevents water molecules from binding tightly into fog and instead forces them to bond into large droplets. Do this method right before you dive, though, because if the spit is allowed to dry, it will not work.
Baby shampoo is said to work as well as any commercial defogging agent you can pick up at specialty diving stores. Just rub a few drops into the lens before you go snorkelling and briefly rinse with water. It is recommended to use baby shampoo because it won’t irritate your eyes if you happen to get some in your eye.
There are of course many other ways to prevent your snorkelling mask from fogging up. If you wish to know them, a bit of light search engine digging will turn up a bunch.