one part of the screen shows a depth of 19.4 ft and below that number is the 22.1 ft depth. which depth reading is the real depth under the boat. that confuses me.
QUOTE=rnvinc;3687678]Correct ... Targets directly under the boat will show in both left SI and right SI ...
Distance to targets in SI (out to the side) is calculated as "slant range" to targets ... (that geometry Pythagorean thing) ...
Attachment 314321
Right Triangle Calculator with detailed explanation
Rickie[/QUOTE]