Preparing a new dive mask
The foggy mask: I had a client buy a new dive mask this week, and I told him to make sure to rub toothpaste on both sides of the mask lens before jumping into the water. It will help prevent the lens from fogging up.
He then asked a very simple question, “Why?”
I had no answer for him—I said it was tradition. He then asked, “But why is it the tradition?
I smiled and thought to myself how living with a Hall of Famer who really is a diving professor, Professor Margo of the department of Oceanic Adventures at Kids Sea Camp, makes me a little dumb at times. I have watched Margo put toothpaste in our new dive masks for years — she even puts it in the old ones at the beginning of the summer. And the dumb part  — I never once asked why. Not once did I ask why we are putting something I put on my teeth every day on an item that has no teeth? I just knew that when she didn’t use the toothpaste, my mask would fog up — very quickly — and I hate a foggy mask.
One good thing about myself is that once I realize just how stupid I’m acting or thinking, I tend correct my behavior, and I do this by gathering information. So here’s why my Oceanic Professor puts toothpaste on the lens of our mask almost every year, at the beginning of our diving season— new or not.
Toothpaste is a mild abrasive
Most newer masks, frames, skirts, and straps are made of silicone, which creates a film on the mask’s lens. The film on the lens blocks the defog from working properly. In fact, if the silicone residue is not removed, any amount of defogging work on the lens.
After the toothpaste
After you have cleaned off the toothpaste and you are heading to the boat, make sure to have some defog. There are many brands, and with the silicon residue removed, most of them will work. The fact of the matter is, all the dive boats have some form of defog, though most use a watered-down J&J baby shampoo.
Other forms of defogging
Spit: Real divers don’t use defog; they spend a lot of time draining their mouths, building up a large quantity of saliva, and projecting it into their masks. Many divers say this is the best form of defog, but the idea of my eyes breathing in all the wonderful germs from my mouth — just doesn’t work for me.
SeaDrops: Clean, quick, and easy to use — a few drops on the inside and the outside of the mask has gotten me close to a decade of “no fog” mask. Just remember to wash the drops out right before you jump off the boat. If you don’t clean the drops out of the mask properly, you could experience a severe burning sensation in your eyes — and the eye burn can really ruin a great dive. Why? Because all defog is a form of soap. That’s why most dive boats and shops use J&J Baby Shampoo  — it’s easier on the eyes.
Burn it off: Don’t do this at home unless you know a professional mask burner who has done it many times. You are basically burning off the thin film that protects the new lens. The danger, of course, is burning the entire soft silicone that makes your new mask so darn comfortable.
After the dive
Hit the dunk tank: Make sure you use freshwater to clean off all your dive equipment. Almost all our family of divers dunk their BCs in the sweetwater tub, but I have watched numerous divers forgo a quick rinse of their fins, mask, snorkel, and wetsuit. Remember, a clean mask doesn’t fog up as much, and clean gear lasts longer.