Explore the fascinating world of underwater navigation with this vintage trade paperback by Ralph D. Erickson. Written in 1979, this illustrated nonfiction book is the perfect addition to any scuba enthusiast's collection. The book covers various topics related to scuba and snorkeling, including tips and tricks for underwater navigation.

Published by the Professional Association of Diving Instructors (PADI), the book is intended for adults and is an excellent resource for those looking to expand their knowledge of scuba diving. The book is written in English and is in very good condition. With its detailed narrative and interesting insights, this book is a must-read for anyone interested in scuba diving.