When writing this course book, the author, Attila K. Kollár took into consideration the expectations and rules of international diving instruction. The seven chapters describe the history of snorkel diving, the UEF diver instruction system, the equipment of snorkel divers, the method of performing dives, and the solutions to be applied when encountering problems while diving. To present the "dry" facts of physics and physiology, the author chose to describe an imaginary dive to supply the relevant information. The book gives a detailed view of the living and non-living environment of dives, and addresses environmental protection and conservation.