Quote Originally Posted by fpt View Post
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