This book is intended for a wide range of fishermen who want to get acquainted with modern radio-electronic devices that provide significant assistance in fishing. The book outlines the principles of operation and the basics of using the most popular and accessible devices - fish-finding echo sounders and satellite navigation receivers, which allow you to detect fish and remember the right places. At the same time, taking into account the qualitative changes taking place in the last decade in the technical equipment of fishermen, primarily with ships, the reader is invited to get acquainted with a number of other devices that are not directly related to fishing.