Snorkelling manual : a guide to snorkel diving techniques for the use of instructors and pupils in the BS-AC National Snorkellers Club /
Blandford, Lionel Frederick.
British Sub-Aqua Club.
London : British Sub-Aqua Club,
1976.
Includes index.
Previous ed.: published as 'The British Sub Aqua Club snorkelling manual. 1974'.
Skin diving