Long ish post, TL;DR at the bottom.
Hello SB, I am a divemaster assisting an instructor with a PADI Open Water course. In this particular class, there is a parent/teenager duo that I have been working closely with. The reason for this is the parent has been having trouble with nose breathing and consequently dealing with water in their mask.
We are on week three of their five week program and the student has been unable to stay down in the deep end longer than a minute or two and they are now getting frustrated because their difficulties are holding up their child's learning. They also have an international trip scheduled soon that they wanted to be certified for.
Due to this student's difficulties I have been working with them almost exclusively, walking them through in my best words how to focus on just breathing through the mouth while in the shallow end and just sitting and relaxing underwater to get the technique down. The Student does kind of alright while in the shallow end, but still complains of difficulty getting a full deep breath because they can't breathe through their nose. Once in the deep end they can only last about a minute underwater until they surface because of lack of deep breaths.
Last week I got the Student pretty comfortable and through many of the skills, the only one we had trouble with on the skills that can be done in shallow water was the 1 minute no mask breathing. Since last week, the student didn't practice at all (instructor recommended breathing at home with mask on focusing on not using nose) and this week they had regressed to hardly even being able to stay under in shallow water. They are now more frustrated than ever because they though they could just jump right back in this week and be at the same mental place as last week and that was not the case, further holding them and their kid up from finishing the class.
Anyway, my question to you SB dive professionals is what strategies do you recommend for students that have trouble with nose breathing I could try with this student? Any help is appreciated!