NorthStar 490 Echosounder, Руководство по эксплуатации

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Chapter 6 - Reviewing past echoes using SoundTrac
490 Echo Sounder Operations Manual Rev. B2 Page 6-3
Echoes from the last 3000 pings are stored. If you try to move
the position marker beyond the oldest echoes stored, an alert
is sounded.
The number of minutes of past echo data available depends on
two factors:
• the depth of the water
• the advance speed
In deeper water, the 490 pings at a slower rate, so the echo
sounder saves data over a longer period of time. A slower
advance speed will have the same effect.
Marking fish as waypoints
The fish marking function lets you use SoundTrac to mark
fish, wrecks, or any other objects that you see at any
past echo
displayed on the screen.
To mark echoes as waypoints:
1. At the
ECHO
screen, press the
CURSOR PAD
to the left to
move the position marker—a dashed vertical line—to the
position of the echo.
2. Press
MARK
.
A *MARK##* waypoint immediately appears on the
SOUNDTRAC screen and on the CHART screen. Each
marked echo becomes a waypoint (named *MARK##*)
stored in the waypoint database. You can perform all of
the usual waypoint functions, including going directly to
this waypoint, adding it to the end of your trip, changing its
name, etc.
Navigating to a past echo position
On the
SOUNDTRAC
screen, the
GO TO
function can be used
for any of the following functions:
• to go directly to a past echo position
• to add a past echo position to the end of your trip
• to store a past echo position as a waypoint or avoidance
point