Furuno CHS-5LMARK-2-55, Operator'S Manual

Page: 39 / 90

3-1
3. ADVANCED SONAR OPERATION
3.1 Tracking a School of Fish (target lock)
Target lock, which requires speed and heading inputs, automatically tracks a fixed lo-
cation (such as a reef) so that you won't lose sight of it on the display screen.
1. On the sonar display, operate the trackball to place the trackball mark on the lo-
cation you want to track.
2. Press the TARGET LOCK key.
The target lock mark appears ( ) on the echo selected and the bearing mark bi-
sects the echo. Horizontal range, depth and bearing to the target appear at the
bottom right hand corner of the sonar display. Note that target lock is automatically
cancelled when the echo moves 1.5 times the range in use.
Target lock mark and target lock data
3. To cancel target lock and erase the target lock mark and bearing mark, press the
TARGET LOCK key again.
Note 1: If automatic tilt is active it is automatically canceled. It is resumed once target
lock is disabled.
Note 2: Target lock feature is canceled when the position selected is more than
1.5 times the range.
Note 3: The target lock feature tracks a target up to 55° tilt angle. For example, if a
ship moves from position A to position D, the target lock works between positions A
and B. The tilt angle is fixed between positions B and C is 55°, however calculation
continues internally. Target lock is restarted after position C.
Target lock and tilt angle
B
Target lock
bearing mark
Target Lock Mark
Target Lock Data
650 (Horizontal range from own ship to target)
153 (Depth of target)
* Relative bearing format may be selected with
[OTHER MARKS] on the [MARKS] menu.
** Any value which exceeds 9999 is displayed
with four asterisks (****).
NNE (Relative bearing to target*)
A B C D
Depth
55° 55°