Thread: Best Down Image for Still Fishing.

While sitting still...Sonar (2d/SI/DI) is going to display structure as solid lines scrolling across the screen...

This is because sonar is not a camera looking down into the water....

Sonar is repetitive sound pulses (pings) sent thru the water ...and then the returning echoes (in the individual pings) are plotted onto the screen in a strip 1 pixel wide...then the next ping data is plotted onto the screen in a strip 1 pixel wide...."pushing" the previous ping data's single strip of pixels into the sonar "history" across the screen...

It is this pinging, plotting, stacking (of the thin strips of echo information on the image) .... That builds the sonar image on the screen...and creates the "scrolling" effect seen we see in 2d...SI...or DI....

If there is structure in the sonar beam at "x" feet away from the xducer...the unit will repetitively "Paint" that echo at the same pixel in the scrolling image over and over and over....creating a solid line at that "x" feet in the image...

This is not to say that structure cannot be descerned in a stationary position...it merely means sonar is not going to "paint a brushpile looking brushpile" sitting still...(with the exception of 360 and maybe the new SpotlightScan from Lowrance)...

Rickie