sAosknATrheGuys
by jeff boyer
Sonar GPS Workshops LLC
A
t a seminar Capt. Jack and i presented
a few weeks ago, one attendee raised
a great question when explaining his
difficulty returning to previously marked waypoints. When he marked structure with a
waypoint, then returned later to that waypoint,
he found the unit was not putting him accurately
back on the structure. He wondered if his unit was
defective.
When it comes to GPS accuracy, some factors are out of your control. But one way to insure the best accuracy possible for returning to waypoint structures is in how you create the waypoint in the first place. if you’re like most anglers, you probably create most of your waypoints using the following method: the structure appears on your sonar screen, you quickly save it as a waypoint (usually no more than two keystrokes required), and done! You’ve got it! diagram 1 below is an example of this approach in action, creating Waypoint 1 to mark the structure on the far right of the display.
if this is your method, you’ve probably discovered some waypoints put you back on the structure consistently time after time, while other waypoints seem to be a challenge getting back on the structure. You might also have found deeper structures are more challenging to get back onto than shallower structures. Here’s the reason. This method creates a “current position” waypoint, which is the position of your boat at the time of creating the waypoint. That might, or might not, be the position of the structure. Most likely, it’s not!
it’s important to remember, just because you can see the structure on the screen doesn’t mean it necessarily is directly below the boat. Seeing the structure on the screen simply means it is in the cone angle of your transducer. and that’s only true if the structure is actively updating on your screen. if its image is completed and traveling across your screen, then it’s not even in your cone angle. it’s “history”; somewhere behind the boat, as the structure in the middle of diagram 1 above. even
DiAgrAM 1
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DiAgrAM 2