Chachacha and kittygilchrist,
My entire life, almost daily, I face my fear of suffocation. Having said that, I have scuba dived and seen the movies that you have mentioned and found that my fear is *my* fear and that when watching those kinds of movies have not been placed personally "at the scenes" so have been able to remain above my fears and enjoy the movies for that which they were intended.
They are good movies so I suggest you both take the risks. I think you will find it worth your while. Simply MHO