Lowrance GPS Locking up when trolling

[OrangeBarrel]

My X-15 has a bad habit of locking up while trolling real slow. I have to turn it off/on to get it going again and it works for awhile then locks up. Has anyone else had this proble? I have to the v2.2 update and can't figure out why it is doing this. Everything else still works, i.e sonar, time, water speed. It's just the GPS trail/speed.

[Gregg Wollner]

If you go into GPS setup, there is an on/off for GPS pinning. Turn it off and your problems will be solved.

Pinning takes an average of your position so when you are moving slowly you are averaging zero.

Easy fix,

Gregg Wollner

[REW]

Depending on the model, some of the gps units use -
"posiiton pinning"
"anchor lock"
or other names.
Basically, they all do the same thing - freeze the gps - if the position appears to be changing very slowly, or if the speed is very slow.

Obviously trolling meets both of these criteria, and thus - causes the gps to freeze. Exactly as designed.

Clear the position pinning in the gps menu - setup screen, and you will be fine - as the previous post suggests.

Take care
REW

[TJ]

After turning position pinning OFF, try changing the GPS update interval as well. When trolling, I will increase the update time to 5-10 seconds or more. I believe it will give you a more accurate speed reading than a very frequent GPS update interval (1 second or less).

Here's my theory: When trolling, you are moving across the earth's surface at a very slow speed. If you are trolling at one (1) mph with your GPS update speed set at one second, you will travel 1.467 feet every second. Introduce the random, variable error in the GPS signal and the vertical and horizontal position change from waves (say 1.467 feet for example), and your GPS might calculate your positional change from 0 feet/sec to 3 feet/sec. That will show on your GPS as your SOG jumping around from 0 mph to 2 mph or more - not good if you're trying to maintain 0.7 mph.

Lengthening the update frequency allows your boat to travel a greater distance between readings. For example, let say you set the update frequency to 10 seconds. Trolling at 1.0 mph, your boat will travel 14.67 feet in 10 seconds between updates. Introduce the same random error of +/- 1.467 feet and your GPS will calculate your distance travelled between updates between 13.203 and 16.137 feet. That translates to 0.9-1.1 mph. As you can see, this will give you a much better idea of your SOG.

That said, if you are using your GPS as a navigational aid in any way when cruising at high speed, increase the update frequency to 1 second. You don't want to find you've strayed out of the channel 8 seconds after the last position update!

TJ