Humminbird TCR ID-10 - Manual (Page 15)

60' scale and it changes to the 0-30' scale, the entire screen will look as if you had been
in the 0-30' range all along.
2. Using zoom and bottom-lock. Through Pixel Memory Capacity, the memory in the TCR
ID-10 stores readings in much finer detail than is displayed in the "regular mode. So
when you activate the zoom or bottom-lock functions, the entire screen changes to
display the up-close detail that is stored in memory. Then when you turn off the zoom or
bottomlock, the whole screen will change back to the full depth scale.