Chart speed for me is 5 or 6. Any faster I'm not getting all the info.
I have to change setting's with water depth how far I'm shooting out the side. If the water is shallow I don't run the SI out over 75ft as this gives you the best pictures.

This one above is 12ft deep and out the side 86 ft. Some people try to set the unit and never change the settings. It does not work as good doing this. Also these shots are from the old unit the 987c-SI

This shot was me finding a school of crappie in winter time. On a lake I had never been on. In less then 10 minutes I had found these. Then caught fish out of this school of fish also.
But if I had not changed the settings, I would not have found these.
Pete