To an untrained, uniformed diver, deep diving does not appear to be that much different than diving in shallow water. This may very well be true when looking at it from a purely physical standpoint. However, as we have outlined in this chapter, this is not the case. Deep diver’s tissues undergo much more nitrogen loading and increased saturation, while psychologically, they must be more disciplined and pay greater attention to their instruments, equipment and surroundings. After reading this chapter and applying the knowledge presented while learning the skills and techniques from an SNSI Instructor, SNSI Advanced Open Water Divers should be able to plan, organize, manage and conduct a deep dive comfortably and confidently.