Thread: Discussion on Lowrance Elite 5 DSI/Chartplotter ....

Even with contour tracking, the fisher is operating within the margin of error of the plotter. Bear in mind that most of the time, the plotter is pretty accurate. It is mainly when almost at a standstill that the problem you describe is most pronounced. Here is something that you can try. When leaving to go fishing, turn the unit on. When you get to the lake, save the trail that the plotter has recorded. Do this each time you go fishing. After a few trips, display all of the saved trails. You will see that even though you are driving the same route, within a metre or so of being on the same course, the trails will not line up with each other exactly.

When zoomed in you will see that the trails may be separated by as much as the three to five metre error of the plotter. Even when contour tracking, the fisher is not going to hit the desired mark every time and that is why the plotter should be used in conjunction with the sonar in these situations. The plotter will get you close and the sonar will let you home in. Let's face it, if you could get bang on the spot every time, then they wouldn't call it fishing, they'd call it catching!

Re: handle on the trolling motor. This is most unlikely to be affecting the operation of the plotter (though you could check this by checking the GPS status when the handle is over the unit.) The pattern of GPS satellites in orbit is random, but generally spread so that there will be satellites overhead, partially overhead and on the horizon. Only three satellites are required to obtain a "fix", though the more satellites that are in view, the better the fix.

Cheers

away,

Thanks for the input. They'll always call it fishing if Im in the boat.

Thanks again, fpt

Hi folks, Id like to pick up again on the elite 5 dsi unit. Spent a couple of days on the lake this weekend, and still had problems with the gps. The wind was favorable for slow drifting the shorelines. I was using the dual screen; 1/2 chart, and 1/2 dsi. According to the "sog" the wind was drifting the boat along about .3 to .7 mph. Now here comes the problem: I could drift for extended time and distance (several minutes and several hundred yards) and my position as indicated on the chart would not change. If I used the trolling motor to change my distance from the shoreline, and got the "sog" up to 1 mph or higher then the chart would update with the accurate position. Is this the nature of the beast or is my unit defective?

Thanks, fpt

Originally Posted by fpt

Hi folks, Id like to pick up again on the elite 5 dsi unit. Spent a couple of days on the lake this weekend, and still had problems with the gps. The wind was favorable for slow drifting the shorelines. I was using the dual screen; 1/2 chart, and 1/2 dsi. According to the "sog" the wind was drifting the boat along about .3 to .7 mph. Now here comes the problem: I could drift for extended time and distance (several minutes and several hundred yards) and my position as indicated on the chart would not change. If I used the trolling motor to change my distance from the shoreline, and got the "sog" up to 1 mph or higher then the chart would update with the accurate position. Is this the nature of the beast or is my unit defective?

Thanks, fpt

Thats pretty much normal for any GPS.

fpt .... I noticed my chart not updating often, when I was just drifting by wind & not under power of the TM ... BUT, I don't remember ever drifting more than 50ft without seeing the icon move.

I don't know if it's related, but what distance do you have your unit set to ... as far as GPS units ?? I have the unit set to the lowest it registers (10ft), but the GPS chart will only zoom down to 20ft. Maybe the unit takes into effect how much distance you allow the GPS to err ? Sorry I'm not communicating with the proper terminology, but I'd have to rig up my unit to find the settings & menu names that I'm thinking of ... so if this only confuses you, as to what I'm talking about, let me know and I'll get back with you (when I have time to rig up the unit @ home & find the settings I'm talking about. (or unless someone else knows & can explain it better, or knows if it's even a factor)

... cp

Its going to be a couple of weeks before I get a chance to use my unit again. Ill check the settings you're talking about then. One thing I wonder: Is it possible that there may be a manual reset feature to make the chart update. A couple of things Ive noticed are: (1) The chart updates just fine when moving over 1 mph. (2)The gps must be working even below 1 mph because the "sog" displays what Im assuming is the correct speed. One way to make the chart update would be to turn the unit off and then turn it back on. Then it would acquire its new position with the satellites. That shouldn't be necessary though.

fpt

Originally Posted by fpt

Its going to be a couple of weeks before I get a chance to use my unit again. Ill check the settings you're talking about then. One thing I wonder: Is it possible that there may be a manual reset feature to make the chart update. A couple of things Ive noticed are: (1) The chart updates just fine when moving over 1 mph. (2)The gps must be working even below 1 mph because the "sog" displays what Im assuming is the correct speed. One way to make the chart update would be to turn the unit off and then turn it back on. Then it would acquire its new position with the satellites. That shouldn't be necessary though.

fpt

Yeah, I don't know what the refresh rate is for the GPS of this unit ... but it will definitely tell you that the boat is moving less than 0.5mph, even if the boat icon isn't moving.

I think that if you have the setting dialed down to the 10ft range, and your chart zoomed in to the 20ft range ... that's all you're going to get out of it. That's the most accurate it's going to read, regardless of speed. That's one reason I always have a marker buoy handy ... so, even though I don't try & be that accurate with the chart icon, I do have the spot marked, even if I drift off from it. Actually, what I've been doing is to use the TM to home in on the spot (with the chart on full screen), and when I get close to putting the icon on the waypoint mark I put up the split screen & watch for the brush to start showing on the screen, then drop the marker & flip the screen over to full screen sonar. I know where the brush is, in relation to the marker buoy, so even if I drift way off (in any direction), I can get back on the brush. That works best for me, when fishing a solo spot or several spots that are in close proximity ... if I'm working a LINE of brushpiles/waypoints, I usually don't drop markers, and just use the split screen to keep me heading towards the next waypoint. I could use the trails/route feature, but haven't needed to, yet.

With the minimum distance that the GPS is calibrated for, for an accurate marking (~ 30ft) ... I don't think turning the unit off & back on to refresh is going to help, since you're likely to be drifting while the unit is acquiring satellite lock. I think the best you're going to get out of a GPS system, especially when drifting slowly, is a icon move after you've drifted more than 30 feet from your previous position. That's about 2 boat lengths, for me ... and even a light breeze can push my bow mounted unit/GPS a couple of boat lengths away from my last position, in only a matter of seconds. (which is the biggest reason why I drop marker buoys, since I don't drop an anchor .... 'cause I ain't got one )

... cp

Getting the Most out of your Lowrance DSI Unit - The Hull Truth - Boating and Fishing Forum

Interesting read . Have mine mounted on the TM as well.