A sure way to keep your mask until it wears completely out is keep it around your neck, until your all the way past the surf, and from that point don't ever take it off over your head, to look through it or wash it or anything, because you might drop it. Only slide it up and then pull the strap up. Just the other day for the first time I got out and someone was squeezing out anitfog (in the water) and I took off the mask to get some, seems safe, but it's a way to loose a mask, do it on shore! Even jumping off boats, leave it around your neck, you're you'll keep it for a long time!