Nothing kills the moment underwater like a mask that won't stop fogging. The good news is that it's almost always fixable, and it usually comes down to two separate steps that people mix up: cleaning a new mask once, and using anti-fog before every single dive or snorkel.
Why masks fog in the first place
Every mask leaves the factory with a thin layer of silicone residue on the inside of the lens, left over from the manufacturing process. Until that layer is removed, no anti-fog product will work properly — the silicone stops it from binding to the glass. This is the single most common reason a brand-new mask fogs badly on its first few uses.
Step 1: Pre-clean a new mask (once)
Before you use a new mask for the first time, give the inside of the lens a proper clean with a mild abrasive. A dedicated mask cleaner like Gear Aid Sea Buff Mask Cleaner is designed exactly for this and won't damage the lens coating. Toothpaste or a baking-soda paste can work in a pinch, but they're more abrasive than a purpose-made cleaner and it's easy to overdo it.
Place a small amount on the inside of the lens and rub gently with your finger — avoid brushes, which can be too abrasive. Rinse well and repeat three or four times. Don't use a lighter or naked flame to "burn off" the residue; it's a common myth, it voids the warranty, and it can damage the mask seal.
Step 2: Apply anti-fog before every dive
Once a mask is pre-cleaned, anti-fog needs to be reapplied before every dive or snorkel — it's a maintenance step, not a one-off fix. Anti-fog works by leaving a thin film on the lens that stops moisture from beading into droplets. Apply a small amount to a dry lens, spread it evenly with a fingertip, leave it for two to three minutes, then rinse gently just before you get in the water. A slight film should remain on the glass; rinsing it completely off defeats the purpose.
We stock a few options depending on what you want: Gear Aid Sea Drops Anti-Fog is a reliable everyday choice, and if you're caught without any, diluted baby shampoo or even spit works as a genuine backup — it's not a myth, it's the same basic principle.
Step 3: Look after it between dives
Rinse your mask in fresh water after every use and store it out of direct sunlight, ideally in a hard case. UV exposure and heat break down the silicone skirt and lens coating over time, which is what eventually brings the fogging back even on a well-maintained mask.
Browse our full range of masks and snorkels if you're due for a new one, or grab anti-fog and mask cleaner for the gear you've already got.