Position and heading. Sounds simple enough does it not? It is quite simple, but with just a litle insight you can utilize this to your advatage while fishing.
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| Test-mounting a Point-1. |
While GPS tells you where you are, heading tells you where you are going, or more precisly where your boat is pointing. With GPS one can calculate heading as long as the boat is moving, the chartplotter simply takes your position now, wait a fraction of a second and then draw a line from where you where and where you are, that line gives you GPS-heading. GPS-heading is precise as long as your boat is moving at a steady pace, and the GPS gets a good signal from enough satelites to triangulate properly. The problem with heading calculated from GPS, is when you move very slow, drift or anchor. In such cases the calculation gets extremly inaccurate, which again leads to your boatsymbol spinning on the chartplotter (or the whole map spinning if you use "heading up") or no updates on heading at all. Point-1 is an electronic compass, thus it has none of these issues and will show true heading regardless of boatspeed.
With the terms sorted out, let us look at what a Point-1 can help you with.
Position from Point-1.
A common misconception is that the position given from the Point-1 is more accurate then that from the internal GPS-receiver in your chartplotter. This can be true, but in most high-end chartplotters of today the internal receiver is just as good as that in the Point-1, so as long as the chartplotter has a clear view of the sky there is no difference in accuracy. If your chartplotter is mounted insida a cabin, or behind steel pipes or solid fiberglass in a console, the internal receiver in the chartplotter suffers from that, and a Point-1 mounted properly will be more accurate. But that is due to mounting, not the hardware itself, and will vary from boat to boat.In a boat used for sportfishing you will typically mount your Point-1 as close to the transducers as you can get it. When sitting at the console idling around looking for fish, your waypoints based on what you see on your sonar will then have position as close to the fish or structure as technically possible. Simply mark what you see on your sonar, and create the waypoint based on that. By amrking on the sonar, instead of hitting thw waypoint-button on your chartplotter, the chartplotter calcultes to your marking and you don`t loose those few seconds of movement before the object you want to mark is visible in the scroll-history on your sonar.
Sett inn video av hvordan man markerer WP på ekkoloddet.
What about the unit up front? If your unit up front is using a transducer up front, typically under your trolling motor (TM) or mounted on a stick, your front unit should use its internal GPS-receiver for position, or you get a marging of error that equals the distance between your unit and the Point-1.
Sett inn video av hvordan velge bort Point-1 som kilde til posisjon.
Heading from the Point-1.
Mounting the Point-1 - Important info!
After reading this far, you might already have started shopping. But before you mount your Point-1, take a few minutes to read the dos and don`ts on mounting it. It might be "un-manly" but start with the installation manual, then take our pointers with you.
As mentioned you typivally want your Point-1 mounted at the back. The problem back there is magnetic interference, caused by steel and electricity. In the first photo in this article you see my Point-1 test-mounted on my Starweld Fusion 16DC, using double-sided tape. We highly recommend doing this before mounting permanantly. Mount it temprorily, then take the boat out and test it through the cycle of RPMs your outboard has, meaning test it at all speeds.
Since magnetic interefrence can be caused by electricyty, and the electricity in the cables in your boat varies with the engines RPMs, it is important to do this test. You could have zero magnetic intereference at idling speed, but still get massive interefrence at full throthle, simply due to your engine.
When testing, you bring up both magnetic heading AND GPS.heading on your chartplotter, and elongate the lines for such directions.
Sett inn video med aktivering av kurs for begge og forlenget kurslinje.
By activating both types of heading on your chartplotter during the testing, you will easily see if there is magnetic interefrence. While the bpat is doing 2+ knots, the GPS.heading will be "true", and if the magnetic heading varies around that, you have a problem with magnetic interference. Keep in mind that you haven`?t calibrated the Point-1 yet (you saw that point in the manual right?) so compass-heading and GPS-heading might not align perfectly, but you are looking to see if the vfariance between them is stabile (good) or changes (not good).
Sett inn video der Point-1 påvirkes av magnet.
As you can see in the video above, the magnet causes the heading from the Pount-1 to wandr off, while the heading from the GPS does not.
Do I need more then one Point-1?
The short answer is "no". If you follow our advice on which units use the Point-1 and which units use their internal GPS.receiver for position, there is no need for more then one Point-1.
Is Point-1 for Lowrance only?
No, it is not. The beauty of NMEA2000 is that it is "industry standard", not brand-specific. The only brand we know of that will not use heading (only position) from Point-1 is Humminbird. We have tested it on Lowrance, Simrad. Garmin and Raymarine with just as good results as with Lowrance. At the pricepoint of Point-1, we currently see no other device that delivers the same quality and functionality from other brands, even though the other brands all have their own devices for position and heading that you can use if you wish to spend more money.
Point-1 can be calibrated in two ways. The easy way is through the menues in your chartplotter, but that only works with SImrad, B&G or Lowrance. If you want to use a Point-1 with other brands, you habe to do the manual calibration. This is explained in the manual, involves driving around in circles for a few minutes.
To summarize, Point-1 is a great tool. Especially for everyone not just fishing straight off the bank but relying on accurate waypoints and catsing-diretion for their fishing.