GPS Question

Discussion in 'SOUTH CAROLINA LAKES / RESERVOIRS' started by JDWILLIS39, Aug 16, 2008.

  1. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    What do you guys get for Estimated Position error on GPS on Moultire or Marion. I have Lowrance 113-HD and it gives 25 to 30 feet position error and I think it should do better. Think it is where I got it mounted but before I do lot of changing I would like to know what you guys get in the area. Thanks for the info.
    Good Fishing
     
  2. flatheadsalyer1

    flatheadsalyer1 New Member

    Messages:
    439
    State:
    Pickens, SC
    I usually only have 15 to 20 feet of position error on moultrie. Haven't fished marion a whole lot. I use a garmin. Being in the military I know that most gps units that are on the market are usually listed to accurate within 25 feet. I seriously think that 25 to 30 feet is really close enough to keep me from changhing a bunch of stuff not knowing if it is really gonna help. Hope this helps a little. Good Luck!!
     

  3. chrisblue

    chrisblue New Member

    Messages:
    1,345
    State:
    SC
    Yeah I'm with Steve on this John.Mine seems to be 15 to 30 feet off on most all lakes.Its really noticable on Santee with channel marker poles though.Its so far off on Lake Greenwood that it will show me driving my boat on land.Thats a mind blower at night time.
     
  4. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    Well guys I guess I am going have to go with you'll. I was talking with fellow (couple weeks ago)who said he got 6 foot or less but after hearing from you guys I went back and read up on Lowrance GPS manual and they say 10 to 20 meters is about best you can expect. I am well within that range most anytime. It is weird when the things on map are not where they supposed to be but it is about 20 to 30 foot error.
    Lowrance said set way point move off and come back and that is how accurate your unit really is. Going give that ta ry next week. Thanks everyone for the input I guess I was just hoping I was doing something wrong and could get better results.:tounge_out:
    Thanks again.
    Good fishing
     
  5. Indigo Flats

    Indigo Flats Member

    Messages:
    382
    State:
    Lancaster,
    Just wondering since you're talking about GPS, how does Loran compare in accuracy to GPS?
     
  6. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Chris, in my opinion, those errors are due to the chartmakers, not the gps. My latest version of Navionics shows them to be pretty much right on the money, unlike the older version. Those folks did an updated survey of Moultrie prior to releasing the 07 & 08 version, and it really made a difference. Contour lines seem to be a little more accurate also.
    Lake Marion, on the other hand, hasn't been updated, so those markers are still located off by a significant margin from where they actually are.
    When Hurricane Hugo redesigned the Santee Cooper landscape, the state opened up a channel, and I guess some of the old channel markers got relocated, but the charts never were updated. Pretty well every chart I've seen is inaccurate as far as the markers are concerned. :roll_eyes:
     
  7. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    JD, my accuracy will vary a little, but it's usually within 10-20 feet or so, but I never have a problem going back to waypoints, including a single brushpile; seldom have to circle to find the mark.
    In the flooded timber of upper lake Marion, a lot of the trees look the same, but my gps will take me directly to the individual tree I have marked, every time.
    I use a handheld garmin gpsmap76, lowrance lms337, and the latest addition in the boat is a Humminbird 797SI, which I don't have much experience with yet, but it also seems to be very accurate so far.
    As long as the error shown is within limits, I wouldn't be too concerned. On the inland salt water areas, I follow trails through narrow creeks, often in the fog, and I've yet to have the gps guide me astray. Biggest problem is that it tends to make me forget to check my compass.....
     
  8. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    Tommy I got Lowrance 113-HD and am still learning to use it. Kind of lost my faith in it for while but your are right my way points are always there it is map that is off.
    ON other hand I always learn lot of things when I get you guys to talking whether it's GPS or fishing so I thank all for the input. I hope be back to lake Tuesday for few days. Try get in some more fishing before water gets to low at Angel's.
    Maybe we can get good rain out of Fay.
    Good fishing
     
  9. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    I started this so thought would report on results. I can get 15 foot estimated error rate most of time. Finally back on water today It was picking up 12 satellites and using WAAS to correct.
    Now objects on my map or 30 feet or more off but if I set way point on stationary object I can go right back to it with seems me less than 15 feet. So I am going leave things like they are and try fish more. Thanks for all input it was appreciated.:wink:
     
  10. blackwaterkatz

    blackwaterkatz Active Member

    Messages:
    3,659
    State:
    Andrews, SC
    Some may disagree with me, but I find better accuracy without the WAAS feature at times. Try it both ways and see what it does for you, John. Like you, though, I never have a problem going back to a waypoint. I've used some coordinates provided by others and actually gone to a single tree on the forested river bank with camouflaged rope tied to it with the intent of not being easy to see. :wink: