You perhaps could start with seal team, on this course he does the first session of open water plus fin pivot and hover but over five sessions. It does take place in the pool only and does not allow him to dive in open water but may give an indication of coping level? The seal team have their own book to study and knowledge reviews but they are much "friendlier" than the "adult" version.
The option after that may be scuba diver which allows the participant to go to 12m with a PADI professional but he would have study the open water book first three sections and sit quizes 1 to 3 on the open water course.
Not sure if this is much help after what you said though
