Humminbird 383c Fish Finder User Manual


 
1
How Sonar Works
Sonar technology is based on sound waves. The 300 Series™ Fishing System uses sonar
to locate and define structure, bottom contour and composition, as well as depth
directly below the transducer.
Your 300 Series™ Fishing System sends a sound wave signal and determines distance by
measuring the time between the transmission of the sound wave and when the sound
wave is reflected off of an object; it then uses the reflected signal to interpret location,
size, and composition of an object.
Sonar is very fast. A sound wave can travel from the surface to a depth of 240 ft
(70 m) and back again in less than 1/4 of a second. It is unlikely that your boat can
"outrun" this sonar signal.
SONAR is an acronym for SOund and NAvigation
Ranging. Sonar utilizes precision sound pulses or
"pings" which are emitted into the water in a teardrop-
shaped beam.
The sound pulses "echo" back from objects in the water
such as the bottom, fish and other submerged objects.
The returned echoes are displayed on the LCD screen.
Each time a new echo is received, the old echoes are
moved across the LCD, creating a scrolling effect.
When all the echoes are viewed side by side, an easy to
interpret "graph" of the bottom, fish and structure
appears.