I'm assuming that you're referring to the National Geographic diver program. My husband and I did this as part of our open water course. For new divers, the program requires an additional two dives plus additional pool time. The "skills" it covers is bouyancy, navigation, fish ID, and conservation.
The first dive we were required to demonstrate mastery of bouyancy in the heads up, heads down, and horizontal positions. Additionally, we did navigation with a compass of squares and triangles. We also covered navigating by using landmarks.
The second dive involves the completion of a project. We had the choice of doing fish ID or completing a map of the area. In the end, our project actually was a combination of the two. (Map of a section of the reef with a list of the fish that swam through during the time of our dive.)
For us as new divers, the course was money well spent. The task loading during the final dive reinforced all of the other skills we had learned and was an amazing confidence booster. Additionally, we felt that the focus on bouyancy control was quite valuable.
For a more experienced diver, I'm not sure it would be worth the money. Unless the project aspect is something you're really interested in or you're looking for additional time with an instructor, there are probably other, more valuable classes out there.
