After you become an Open Water Diver, you have 3 advanced ratings you can achieve through continued education and regular diving. These ratings are not specific classes, rather are awarded after the completion of a certain number of dives and Advanced Specialties. After these 3, you can progress into the dive leadership program.
The 3 Ratings
Specialty Diver
Dives: 12
Advanced Specialties: 2
Advanced Open Water Diver
Dives: 24
Advanced Specialties: 4
Master Diver
Dives: 50
Advanced Specialties: 5*
*One of the specialties must be Stress and Rescue