My only point is if you take a cup into the water upside down it won't fill with water! Diving bell etc! It will compress the air the deeper you go, but if you didn't equalize with you nose your eyes would pop out! The only way for water to come in is air to leak out! My face hair has nothing to do with it sense it is under my mask. It is about displacement and fit, but not face hair. Unless you have Captain Kangaroo eye brows!