Gadget with which objects are detected and situated inthe middle of the sea, with the echo of ultra-sound waves. It is made of a source of ultra-sounds that emits conveniently directed pulses. The echo of the sound wave is received and registered, allowing the localization of a reflected object.The pulse spectre emitted by the gadget is in most places of ultra-sound regions, since usually they operate in a band of 5000Hz and 50000Hz frequency.