Hey there, just a gentle note to mention that quite often, a person who is swimming and on the verge of severe panic or death by drowning is very pasive while struggling on the surface. This is caused by severe exhaustion or lungs filling with water. The person in trouble often goes un-noticed by others and just dissapears under the water. This is very,very common when analyzing death by drowning events. Also, try to understand that wearing the mask as noted in the OP, is a very common sign of distress. It is most always the first or second thing divers do when they are on the surface and highly stressed. Being that this is true, it is generally safer and wiser to avoid wearing the mask in this way if you are not in trouble. I am not trying to flame anyone by this post, just adding to the conversation.