Good afternoon. I do not know what I touched, that from a certain moment, when moving the mouse by the content of the tracks, this movement is accompanied by an annoying vertical line, showing the exact time of the position of that line. Is there any way to avoid it?
My apologies, my language is Spanish and I turned to Google Traslate.
Greetings and thanks.

Aim Assist on the Edit menu, keyboard shortcut X

Not in front of Sonar at the moment, but if I recall correctly you hit the "X" key then you can toggle it on and off...

Scook beat me to it..

Finally!!! Thank you!! What a joy I have !!!

For me, in Track view, you get to this under View|Display|Aim Assist.
 
I use it a lot when splitting or trimming clips, but I agree it is annoying when you aren't using it or don't need it.
 
Exaple: Cutting vocal clips in 12 tracks so the clips all start on the same beat and can easily be copied and pasted into another Chorus. (Obviously, make the clip start a beat or half beat before the actual sound begins.)