divinh
Contributor
In a perfect world, you'd pay for a group lesson (cheaper than private lesson) and there'd be both an instructor and one or more divemasters. When a student in this setting struggles, the divemaster can focus on assisting them while the instructor works with other students. Done well, the struggling student will catch up to the rest of the class before they've gone too far.
From what you wrote, it sounds like there wasn't a divemaster present, just the one instructor?
Where is the line drawn between assisting and instructing? Once a skill has been demonstrated by the instructor, can the DM's then watch over and correct students?
Getting help from his wife already sounds verboten, but has been given as advice.