Humminbird 360 question

For those of you using HB 360, I have a distance question. In this video at the 3:10 to 3:50 mark, he explains how far away the school of fish is from his hole and the transducer.

https://www.youtube.com/watch?v=aqbB-hjFY3c

Is this correct? It seems as though it should be about 20' to his right, not the 10' that is listed in his little diagram.
Or is it about 60' as they are pretty much on his range line? I'm confused!!

Wondering if this 360 is something I want to get in to, to maximize my time on the hardwater but having trouble deciphering the distance thing. I get it with side imaging so I should be able to get the drift of how it works with 360 imaging.

I think is was here on cdc that I read that in water less than 30' deep or so, the slant line distance and the range line distance is a "near enough, close enough" situation. His water is a bit deeper so the trig computation is a bit more on the hypotenuse.

I’m gonna disagree with his calculations ...if he is, in fact, in 42’ of water ...
Attachment 407726
Right Triangle Calculator

Using 360 or SI —> water depth (side “a” of a right triangle) and slant range to target (side “c” of a right triangle) are usually known ...

Horizontal distance (side “b” of a right triangle) is calculated using Pythagorean's theory “a ² + b ² = c ²” ...

(or just use any internet right triangle calculator like in the link provided) ...

Rickie

So we can consider the range lines on 360/SI as "slant line range lines" rather than "horizontal distance range lines"?

Thinking on this a bit more, I wonder if he had cursored over and marked it, would the distance have been displayed as about 42' or about 60'? Transducer is not moving so the distance figure wouldn't change as it does in a moving boat when you freeze the display and put the cursor on a target.

Correct ... range lines on 360 and SI are “slant range lines” ...

Rickie