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Spring 2019
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on your chart screen because the internal antenna can’t know where your boat is pointing.
If your chart is set to “North Up,” when your boat stops moving the GPS loses its ability to rotate the chart so North is at the top of your screen. Your screen may start spinning as your GPS tries to establish the direction your boat is moving. How confusing is that?
SOLUTION #1
The solution is to add the Lowrance Point-1 to your NMEA 2000 network. The Point-1 is both a GPS receiver and a heading device. Because it has a built-in magnetic compass, it accurately displays the direction your boat is pointed on your chart, and which way is North, even when your boat is stopped.
Imagine you are fishing a waypoint loaded with bass. Upon arrival, an internal GPS receiver would initially show the correct location of the bass on the chart display since the boat was moving. Once stopped, a slight breeze or momentary use of the trolling motor turns your boat ninety degrees while essentially remaining in the same spot. If you continue to cast where your chart displays the bass’ location, you will be ninety degrees off.
If you are wondering why fishfinders have an internal antenna and still need a Point-1 external antenna, you are about to find out. Some anglers have no need for the precision bass anglers favor, so internal GPS receivers are all they need. But there are significant advantages to having both the internal receiver and a Point-1, especially if you use more than one fishfinder on your boat with multiple sonar transducers.
PROBLEM #2
Why are my waypoints sometimes not accurate? Most of us have multiple GPS units, and we record GPS waypoints while sitting in the driver’s seat, or when at the bow using the electric motor. With an ethernet cable, each waypoint is shared on both the bow and the console fishfinder, with the coordinates of the GPS receiver’s location used to record them.
If both the bow and console fishfinder are using internal receivers, the GPS coordinates saved when recorded at the bow will not be accurate when returning to the spot using the console GPS receiver, or vice versa.
Here is how I recommend mounting and using a Point-1 for most bass rigs like my Ranger. I mounted the Point-1 as close as possible to both my StructureScan transducer (SideScan and DownScan) and my regular sonar transducer (mounted in the sump of the hull). Since the antenna is close to my transducers, this allows me to precisely mark the exact coordinates of what I see on my sonar display when using my console Lowrance HDS unit.
CONSOLE HDS GPS SETTINGS
Set the Console HDS to use the Point-1 as the source for “GPS Data” and for “Heading Data” (go to Pages, then Settings, then Network, then Data Sources).
To set the “GPS Data” next go into GPS, then select Point-1 for the source. For setting the “Heading” select Vessel, then Heading, then Point-1.
SOLUTION #2
Put a GPS Receiver near the bow transducer, and second one near the transom transducers. The HDS unit(s) used at the bow are over top the bow transducer, so the internal GPS receiver works great for recording and returning to waypoints when at the bow.
The HDS unit utilized at the console is many feet away from the transducers it uses, so it would not be optimal to use its internal GPS receiver for recording and returning to waypoints. A Point-1 receiver mounted near all the rear transducers is a better choice when precision matters.
Any waypoint saved by the console HDS takes full advantage of the better accuracy of the Point-1 GPS data, regardless of how you save the waypoint (either pressing the waypoint button on the HDS, or by using the cursor on the sonar or StructureScan screen).
PROBLEM #3
How can I get the Point-1 heading precision from my Bow HDS if I am using its internal GPS receiver for marking and returning to waypoints?