I have a CP180i. This is cut and pasted from the online manual:
3.1.1 Cursor Vs. Home Mode
Cursor Mode
When the cursor is shown on the Chart Page, the chart plotter is in Cursor Mode.
In Cursor Mode the position of the vessel will not stay in the center of the page and will move right off the edge of the screen (as your boat moves). Cursor Mode allows you to pan around and look at areas on the chart. In this mode you can also create Marks, Routes, measure distance and bearings from your current position.
Home Mode
When the ship icon is shown on the Chart Page (cursor is not shown) you are in Home Mode. Now as the ship moves through the water the vessel’s position will be kept in the center of the display.
NOTE
To change from Cursor Mode to Home Mode press [CLR].
I hope this helps.