Furuno CSH-5L/CSH-8L - Manual (Page 45)

3. ADVANCED SONAR OPERATION
3-9
3.7 Collectively Deleting Marks
You may collectively delete track, event marks or fish marks as shown below.
Own ship position mark may be also be deleted, one by one.
1. Press the [MENU] key to open the menu.
2. Use the [RANGE] control to choose [MENU MODE] at the top of the screen.
3. Use the [GAIN] control to choose SONAR.
4. Use the [RANGE] control to choose ERASE MARKS.
5. Use the [GAIN] control to choose item to delete: TRACK, SHIP, EVENT or
FISH.
TRACK: The oldest 10% of the ship’s track is erased with each press
of the [EVENT] key.
SHIP: The oldest own ship mark is deleted with each press of the
[EVENT] key.
EVENT, FISH: All corresponding marks are erased when the [EVENT] key
is pressed.
6. Press the [EVENT] key to delete all of the mark type selected at step 5.
7. Press the [MENU] key to close the menu.