Innovative measuring sounder for hydrographic research, available in two models: single-frequency (SDE-19S, 200 kHz) and two-frequency (SDE-19D, 200 & 20 kHz): - compact and durable construction of the case; - simple and fast connection with an external RTK GNSS receiver; - built-in Wi-Fi and WEB user interface for simple configuration and setting of the echo sounder; - support for exporting several data formats; - optionally available software for Android and Windows operating systems.