Size of graph cone

[Old Gray Hair]

Does anyone here know what the size of the graph image cone is? What I mean is, when I look at the information displayed on my Lowrance X135, how big of an area am I looking at? A five foot diameter circle, a ten foot circle? Does any one here have an idea?
Thanks.

 

[Moody Blue]

Re: Size of graph cone

All depends on what depth you are talking about. Been a long time but I think the typical 200Khz skimmer type transducers have a 15* cone angle.

The deeper the depth, the wider the coverage area. At say 10ft deep you may be looking at a 3ft diameter area while at a 50ft depth you would be looking at a 13ft area.

In reality this is not really true because the ultrasound power intensity drops off rapidly as the beam spreads. So in fact its really hard to interpret just how big of an area you are "looking at" on the display.