Best Ways To Defog Your Scuba Mask

The Best Ways To Defog Your Scuba Mask from the Scuba Leeds team. We often get asked how to stop your mask from fogging up. Spuds, toothpaste, baby shampoo, washing up liquid, spit are all linked… they are all cures to help when your mask is fogging up while scuba diving or snorkelling.

You gear up to put on your mask and start your descent. Your mask fogs up so you can see nothing clearly. This is extremely annoying. Constantly needing to add water to your mask to rinse the fogging out. Then having to repeat this every few minutes throughout the dive. Yes, we have been there too.

We often get asked "What causes your mask fog up?" and "Why does spit stop it fogging up?". So here are the best ways to defog your mask. The definitive guide on how to defog my scuba mask.

Why does it fog?

Fogging is the build-up of condensation; this is water vapor from the air in the gap of your mask. The mask lens is in constant contact with the water you are diving in. This water is cooler than the air in your mask. The water vapor in the air inside your mask comes into contact with the glass of your mask and then cools. As it cools it turns back into a liquid, this is called condensing. These tiny droplets hang on any imperfections in the glass or dirt then block your view by causing fog.

Why does spit work?

We now know the water droplets hang on to the imperfections in the mask. To prevent the mask from fogging up you need to make the surface smooth so the water cannot hang on it. So we find a nice slick, slimy, slippery product that causes the water to slide to the bottom of the mask. This is why spit works.

Why do I need to defog my mask?

Every scuba diving instructor in the world will suggest the best ways to defog your mask. I tell all of the students I dive with to use the anti-fog product of their choice, rub it in well and gently swill your mask put it on and leave it on. We are all divers and we all look the same in a mask so do not worry what you look like. It is important for you to be comfortable, but as an instructor, I need to see their eyes. Communication does not only come in the form of hand signals.

Very recently I was diving with a PADI Discover Scuba Diving candidate, I knew there was something wrong as I could see this in their eyes, but every time I asked if they were OK they signed back OK, When I pointed at them and gave them something wrong signal they nodded and pointed to their ears, so we went up a little until they smiled with their eyes and gave the OK signals and then we continued with our dive. It was her eyes that told me something was wrong and a fogged up mask would have prevented this.

New Scuba Diving Masks need to be prepped before diving this has been covered in a blog Ged wrote earlier. (Read it here!)

So what are the best way to defog your mask?

Defog Method 1: Commercial Defogs

If you don’t fancy spitting in your mask you can buy manufactured defogging sprays by companies such as McNett. These come with instructions but most you drop or spray in the solution, rub around and rinse out. Two of the more popular commercial defogs are the McNett Sea Gold and McNett Sea Buff.

Defog Method 2: Spit

Spit on the inside of the mask and rub it around with your finger. Dunk the mask briefly in fresh water. The goal is to leave a thin layer of saliva on the inside of the glass.

Defog Method 3: Baby Shampoo

Spray a diluted solution of (no tears) baby shampoo and a quick spray rub round and rinse out does the trick. A simple garden plant spray bottle works well for this option.

Defog Method 4: Washing up liquid

As with the baby shampoo, spray, rub, rinse. I used lemon washing up liquid once and it made me sneeze all dive, I think it must have used pollen for the smell. Be careful if you need to rinse your mask as any soap in the eye can really make them sore and it is really hard to rub your eyes with a scuba mask on.

Defog Method 5: Toothpaste

It is likely that you will have used this to prep the mask if you rub and toothpaste on the inside of the mask lens cover the lens completely. Rinse the mask gently with fresh water until the lens is clear. This also made my eyes water all dive I think the extra minty flavor was the culprit

Defog Method 6: Potatoes

A slice of potato rubbed on the inside of a mask lens has been said to keep a mask from fogging. But to be honest who wants to waste one of the best food stuff on stopping you mask from fogging up when you can just spit in it?

User Feedback

Whilst Ged and I were highly skeptical about the effectiveness of a potato on the inside of the mask a recent PADI ReActivate candidate explained that they had had a problem throughout their time diving with fogging. After a brief discussion, Stephen agreed to give it a try for us. Ged sliced off a potato scallop and applied a layer of juice to the inside of his mask. During the dive, I kept an expectant eye on the lens. No fogging! Brilliant, another Top Tip for the Best Ways To Defog Your Mask.

Then the moment of truth removes, replace and clear the mask skill. Stephen completed the task without incident and the rest of the dive with a clear mask. At the end of the session, Stephen was clear "The spud has been the only thing that has ever worked and what a great team of instructors you are. Not just for knowledge but for having a Maris Piper there at a training session for me to use". He went on to ask if we know whether importing a potato in his dive bag is a problem when he goes to Sri Lanka in three weeks for his honeymoon, diving with his new wife.

The team from Scuba Leeds all wish Stephen and Deborah happy diving and long and happy life together.

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