The course consists of three main components: 

1. Knowledge development
   
   During the knowledge development portion, divers learn about the causes and prevention of diving emergencies, and how to respond to them when they do occur. This includes learning about self-rescue techniques, recognizing and responding to stress in other divers, and how to manage emergency situations.
   
   
2. Skill practice
   
   The skill practice portion of the course involves learning and practicing a range of rescue techniques, such as how to perform a rescue breath, how to use a pocket mask, and how to provide basic life support to a diver in distress.
   
   
3. Realistic scenario training
   
   The scenario training component of the course involves simulated emergency situations that the diver will have to manage in order to rescue a fellow diver. These scenarios are designed to be as realistic as possible, and can involve everything from responding to a panicked diver, to rescuing an unconscious diver from the bottom of the ocean.

Overall, the PADI Rescue Diver course is an important step for divers who want to develop their skills and knowledge in order to be prepared for emergency situations and to assist others in need.