Snorkel mask fit vs fog prevention: Fit is the only thing that matters

If the mask doesn’t seal against your face, nothing else helps — you’ll spend the trip clearing water. Test fit by pressing the mask on without the strap and inhaling; if it stays, the seal is good. Silicone skirts beat rubber for comfort and longevity, and low-volume masks equalize easier and fog less. No amount of defogger can fix a leaky mask.