Last Thursday I had a class in the pool for their second night. That means mask removal and replacement will be the fun skill of the night. I knew we were destined for trouble because I wasn't able to practise mask clearing as much as I would have liked the first night. The pool heater was acting up and the temp was down a few degrees and I had cold students shivering before we were even half way through with the night. They were able to clear but there were a few issues I would have like to have worked on.
The water was still chilly this night but I put wetsuits on everyone just to be safe and to make sure we could spend all the time we needed in the water. There were 2 students with issues on the mask. One student could blow through her nose and tilt her head back but was always getting water back into her mask and inhaling it through her nose while her head was back. I couldn't get her to stop inhaling while her head was up. FYI-when you tilt your head back, it opens up the back of your throat and make it easy for water to slide down your nose and coughing and sputtering ensues. After a few tries it FINALLY hit me to swap out masks. This is the situation that cries out for a purge mask. You clear it by blowing out through the nose while your head is in the down position. Since there was no tilting up, she didn't have the reflex to inhale through her nose and the problem was solved.
The second student had his mask so tight that every time he tried to start blowing out, the mask would suction up to his face and he couldn't break the seal. He was a younger diver and I think a little nervous about getting water up the nose. This was easier to solve. You need to start blowing earlier when you are looking down and then continue that as you look up and release the bottom of the skirt of the mask. For some reason everyone can breathe out through the nose easily when you look down. When he did that he broke the seal earlier and didn't get the suction cup action.
These are a few tricks to try if you have issues clearing your mask.