This ed. originally published: 1976.
Bibliography: p.38. _ Includes index.
Snorkelling manual : a guide to snorkel diving techniques for the use of instructors and pupils in the BS-AC National Snorkellers Club by Lionel F. Blandford. ISBN 0902988158. Published by British Sub-Aqua Club in 1977. Publication and catalogue information, links to buy online and reader comments.