Raymarine C90w, C140w manual Bottom Lock, Enabling the Fishfinder A-Scope Mode

The standard fishfinder display shows a historical record of fishfinder echoes. If required, you can display a live image of the bottom structure and the fish directly below the transducer by using the A-Scope feature. The width of the bottom covered by the A-Scope is indicated at the bottom of the window. A-Scope provides a more precise and easier to interpret indication of the target strength.

There are three A-Scope modes, as illustrated in the diagram below:

Enabling the Fishfinder A-Scope Mode

From the fishfinder main screen:

1.Press the appropriate ADJUST... softkey.

2.For dual frequency screens, select FREQ1 or FREQ2 to select which frequency display you wish to change.

3.Press the SELECT VIEW softkey.

4.Use the trackpad up/down to select A-SCOPE.

5.Press OK when complete.

Note: Enabling A-Scope mode automatically switches OFF Bottom Lock and Zoom.

Bottom Lock

The Bottom Lock function applies a filter to flatten the image of the seabed and make any objects on or just above it easier to discern. This feature is particularly useful for finding fish that feed close to the bottom.

Bottom Lock is selected for individual fishfinder windows and can replace or appear alongside the standard fishfinder image. Adjusting the range of the bottom lock image allows you to view more bottom details. You can also reposition the image on screen to anywhere between the bottom of the window (0%) and the middle of the window (50%) by using the Bottom Shift control.

156 C-Series Widescreen user reference