This 57 page manual is recommended for your Deep Diving Specialty which includes two knowledge reviews you will go over with an instructor during your course.
Excerpt from the manual:
"The lure of the deep. There’s something exciting and mysterious about exploring deeper dive sites while scuba diving. Sometimes it’s a wreck that attracts you below 18 metres/60 feet, and on wall dives it may be a giant fan or sponge. Whatever it is, you will learn to scuba dive with confidence at depths down to 40 metres/130 feet."