I have mine on my face from the time I get into the water, till the time the dive is over. When the dive is over, it comes down around my neck. If I am in the water waiting for other divers to enter, and I have my mask anywhere else than on my face at the start of the dive. My mask almost always fogs up. I suppose its because any anti-fog I put on, will be washed off while bobbing in the water waiting. Besides, I feel comfortable with my mask on, so on it stays.