Furuno GP-1650WDF, GP-1650WF Interpreting the Display, Zero line, Minute mark, Fish school echoes

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2.15 Interpreting the Display

Zero line

The zero line (sometimes referred to as the transmission line) represents the transducer’s position, and moves off the screen when a deep phased range is used.

Zero line

Shift

Zero line

Minute mark

Minute mark shows time with two colored bar. Each bar is 30 sec.

Fish school echoes

Fish school echoes will generally be plotted between the zero line and the bottom. Usually the fish school/fish echo is weaker than the bottom echo because its reflection property is much smaller compared to the bottom. The size of the fish school can be ascertained from the density of the display.

2. VIDEO SOUNDER OPERATION

Bottom echo

Echoes from the bottom are normally the strongest and are displayed in reddish-brown color but the color and width will vary with bottom composition, water depth, frequency, sensitivity, etc.

In a comparatively shallow depth, a high gain setting will cause a second or sometimes a third or a fourth echo to be displayed at the same interval between them below the first echo trace. This is because the echo travels between the bottom and the surface twice or more in shallow depths.

The color of the bottom echo can be used to help determine the density of the bottom materials (soft or hard). The harder the bottom, the wider the trace. If the gain is set to show only a single bottom echo on mud, a rocky bottom will show a second or third bottom return. The range should be chosen so the first and second bottom echoes are displayed when bottom hardness is being determined.

Intensity difference in water depth

Second bottom echo

Size of fish school

Small Large school school

Rock base

Mud and sand

Fish school echoes

Bottom echoes

2-11

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Contents Color DGPS/PLOTTER/SOUNDER Color GPS/PLOTTER/SOUNDER 00080936100 Safety Instructions Table of Contents Routes IiiForeword FeaturesWord to GP-1650WDF/1650WF Owners Display Unit System ConfigurationWhat is WAAS? Display Unit Controls Operational OverviewDisplay unit Inserting Mini Chart Card Adjusting Tone and Brilliance LON Menu Operation, Soft Keys Demonstration Display Principle of Operation Video Sounder OperationUnderwater conditions and video sounder display Normal sounder display indications, markers Sounder Display DescriptionKHz picture Sounder function window Selecting sounder display modeMarker-zoom display plus normal sounder display Bottom-zoom display plus normal sounder displayPlotter/Sounder Display Dual-frequency DisplayManual Sounder Operation Automatic Sounder OperationSelecting display range Adjusting the gainRange shifting Suppressing Interference Measuring DepthSuppressing Low Level Noise White Marker Erasing Weak EchoesSelecting Background and Echo Colors Selecting Picture Advance SpeedAlarms Zero line Interpreting the DisplayMinute mark Fish school echoesSurface noise/aeration Surface noise/AerationPresentation Modes Plotter DisplaysNorth-up Course-upShifting the Display CursorDisplaying Nav Information Window Turning on the cursor, shifting the cursorMini Chart Cards Selecting Chart Scale/RangeIndices and chart enlargement Chart icons and their meaningsChart symbols Remarks on chart displaySample chart Japan and South Korea Showing indices Furuno chart symbolsAid to navigation data Port service icons Nav-ChartsTMcardsEnlarging an indication Navigation Data DisplayGPS satellite monitor display Navigation data displaySteering Display How to read the compass displayBeacon information display Beacon information displaySetting the range of the XTE scale How to read the XTE indicationXTE range setting window Highway DisplayPress the HIDE/SHOW key Changing Operation ModeResetting trip distance Selecting fishing 1, fishing 2 modeNavigation Trip Distance Track Track Plotting Method, Interval Changing Track ColorTrack plotting method Track color windowTrack plotting interval Changing Track Memory CapacityInterval window Track memory windowErasing tracks by area Erasing TracksErasing tracks by color Erasing all trackEntering Marks MarkPlotter display Changing displays Plotter displayVideo sounder display Changing Mark AttributesChanging displays Video sounder display Mark/line windowChanging Mark Size Chart details menuMark line window Mark color windowDisplaying Track and Mark Points Erasing MarksTarget Mark Entering Waypoints WaypointsEntering waypoints at own ship’s position Entering waypoints at MOB positionWaypoint window Waypoints menuMark shape selection window Mark color selection windowEntering waypoints by range and bearing Entering waypoints by latitude and longitude position Erasing Individual WaypointsErasing waypoints by the cursor Erasing waypoints through the waypoint listChanging Waypoint Position on the Plotter Display Changing Waypoint DataSearching Waypoints Waypoint Mark SizeSearch window Entering Routes RoutesEntering routes through the route list Route menuEntering routes by the cursor Connecting RoutesConnect route window Inserting waypoints through the route list Inserting, Removing WaypointsChanging waypoints through the list Edit route menuRemoving waypoints from routes Inserting waypoints on the plotter displayCreating Track-based Routes Route contents displaySave route menu New route windowErasing Routes Navigating to Quick Points NavigationSelecting quick point entry method Navigating to a single quick pointNavigating to Waypoints waypoint list Navigating to Ports, Port ServicesPlotter display Sample port list southern ItalySample filling station locations southern Italy Sample port service listNavigate along specific leg of route Following a RouteRestarting navigation Navigate route waypoints in reverse orderSwitching waypoints Setting speed for ETA calculationSelect speed for ETA window AutoWaypoint sw window Canceling NavigationAudio Alarm On/Off Plotter AlarmsAlarm menu Audio alarm windowAnchor Watch Alarm Arrival AlarmSpeed Alarm XTE Cross Track Error AlarmProximity Alarm Alarm messages Alarm InformationAlarm messages and their meanings Formatting Memory Cards Memory Card Operations10-1 Download/upload menu10-2 Saving Data to Memory CardSaving data Save Data messageLoading Data from Memory Card Error messages10-3 Data overwrite10-4 ConfigurationWaypoint/route Mark/lineChart Offset menu Chart Setup Options menuCustomizing Your Unit 11-1Chart details menu description Chart Details menu11-2 Display setup 1 menu Display Setup 1 menu descriptionDisplay Options menu 11-3Display setup 2 menu Display Setup 2 menu description11-4 Mag variation windowGPS Setup options menu GPS Setup Options menu description11.3 GPS/DGPS/TD Options menu 11-5Geodetic datum window 11-611-7 11-8 TD Setup menuDisplaying Loran C TDs Displaying Decca TDsSystem Setup soft key Sounder Setup Options menuRange Setup soft key 11-9Echo Offset 200kHz Echo Offset 50kHz 11-10Seabed LVL 200kHz, Seabed LVL 50kHz TVG conceptSetup Nmea Port 1 menu description Configuration menuSetup NMEA/DGPS Port 2 menu description 11-11UPLOAD/DOWNLOAD Data menu 11-12Upload/download menu Display unit, rear viewConnection of GP-1650WDF/GP-1650WF to PC 11-13Waypoint data format Character available for commentRoute data format 11-14Route comment format End of sentenceInserting Chart Card Using C-MAP NT ModelLocation of chart card slot cover 12-112-2 Cursor and Data DisplayObjects window Example of caution area window12-3 Tidal InformationDate window 12-4SET GO to Method window 12-5 Select Port Service windowSample filling station locations Make route windowLighthouse appearance when sector info is off Setting Chart Setup Options12-6 Sector infoDepth info display 12-712-8 Displaying Program NumberMemory, I/O test results Maintenance Maintenance & TroubleshootingRecommended maintenance program 13-1Simple Troubleshooting Replacement of Fuse, BatterySimple troubleshooting plotter 13-2Simple troubleshooting sounder Error MessagesError messages 13-313-4 Diagnostic TestsMemory, I/O port test Test menuKeyboard test 13-5Display test Keyboard test13-6 Clearing MemoriesMenu Tree Chart Offset Track ControlMenu Tree 2 By soft key Next GRI Loran C ChainsChain Location Code Decca ChainsWorld Time OLD HAWAIIAN-OA Geodetic Chart ListThis page is intentionally left blank General Coating Color Index-1 IndexIndications Index-2Index-3 Index-4