ECHO FISHING. By R.G. Haines.

1969 1st edition. 8vo (142 x 222mm). Ppxiv,116. B/w photograph plates, b/w line illustrations, sonar charts, brief bibliography. Blue boards, spine titled in gilt.

This is "a book for the practical fisherman which explains, in non-technical terms, the basic principals of underwater sound propagation and the methods of applying these principals in modern echo sound and Sonar systems for the fishing industry. The profusely illustrated section of the book dealing with echo trace interpretation will prove particularly valuable". Chapters include: Echo fishing; Sound in water; The echo sounder - transducer, transmmitter, recorder unit display, practice, special applications, distant-water trawling, bottom seining, crustacea, mid-water fishing, chart interpretation, fish traces, fish shoal traces, bottom echoes, other echoes; Asdic - theory, practice, operating procedure - searching procedure, method of training, search range, contact procedure, approach, classification, depth of shoal, method of catching, secondary uses, ground discrimination, chart interpretation; Future developments.