GPS - total distance not very accurate

I recently bought my first GPS (Garmin GPS 72) and since it’s my first GPS, I don’t know a whole lot about operating it. I realize that it’s a basic/entry GPS but out of the 8 times I’ve used it so far, four of those times it’s been way off on max speed, average speed and total distance (the only 3 things I interested in using it for). I’ll paddle 2-3 km or miles but it’ll report the trip distance at over 100 km. Max speed while paddling will sometimes show up to 70km/h.



When it’s finding satellites, it always finds four or more and goes into 3dGPS mode within a couple minutes.



Do I have a defective unit, is it just a case of you get what you pay for or am I doing something wrong? Does my location matter? I’m in a pretty remote area in Northwestern Ontario.



Any advice is appreciated.

Why not call Garmin?
http://www8.garmin.com/support/

Does not sound right .
You can email their help department.

dumb question here
Did you clear the previous history on the trip computer? I have to start my Garmin Rino at zero or it will give me the results for however long it was tracking all the previous times I had it turned on.

Sounds Like Set Up Issues
I regularly use a garmin while paddling. The only way your top speed could be that high is that it was navigating while driving down the road in your car, (or I should take forward stroke lessons from you).



Be sure to reset all your parameters at the begining of your paddle. After reset your max speed, avg speed, distance, time should all read zero.



Start navigating when you start paddling. I typically will just nav to the start point if I do not require nav assistance. That way the unit will tell me how far it is back and what direction to the start, current speed and time info and elapst speed and time info.



This all work just the same if you nav a route or to a WP instead of back to the start.



The trip log is very accurate. I have measured against my car odometer on a long road trip and been well within the accuracy of the car’s odometer.



Mark

resetting
I make sure to reset the trip computer to all 0’s before paddling (I wish there was an option to reset all rather than having to reset each field individually). I also check the progress pretty frequently now so that I have a rough idea of my progress before the numbers get messed up. A few of the times, it’s shown my paddling speed as being a lot faster than my driving speed to the lake.



I’ve submitted a support ticket to Garmin but haven’t heard back from them yet. I was hoping that this is a fairly common problem and someone here might be able to respond sooner than Garmin. In the meantime, I’ll reset the unit and see what happens.



thanks to everyone for the advice.

yep
I reset the unit each time before paddling and it starts off tracking the data good. It usually reports skewed numbers an hour or two into the trip.

good luck
Be persistent, Garmin needs a hard kick in the ass to get them to respond.

Reset all?
On my lowly Garmin Etrex legend, I can easily, (in fact it appears to be the only way) reset the trip computer all at once, all values revert to zero. Are you missing something? Reexamine your instruction manual.

Signal?

– Last Updated: May-29-07 10:22 PM EST –

If you loose your signal along the way it will give erratic readouts, under bridges, under tree cover. Keep it out in the open on deck and don't let it overheat.

I was once paddling with a nubee in a Tampico. When we returned her boyfriend checked her GPS and it said her top speed was 8.6mph, he was impressed. I told him the only way that was possible is if she threw the GPS at me.

Your unit is set in American miles
And you are in Canada. HUGE difference between American miles and Canadian miles.

Ditto on the signal
I’ve had nearly perfect performance from my bottom-of-the-line Garmin Etrex, but one time while hiking, poor signal reception caused it to “lose” one satelite at a critical time, and it pegged my location as being up in the middle of Hudson Bay (I had some reasonable geometrical evidence to suggest that this is what happened). Needless to say, on that particular hiking trip, an uninformed observer would have concluded that I must have been riding in a jet airplane to log so many miles on the trip meter in such a short time. Perhaps errors in position-plotting on a much smaller scale than my example would cause what you are seeing, and perhaps that also has to do with signal reception. Just a guess.


This is a standard feature for Canadians
Since you are freeloading on our GPS satellites we build in an error factor. Your government loves it though - they’ve used it for years to convince Canadians that your country is the second largest in the world.

no, it’s set to KM
I set it to track kilometers. I mentioned miles in the original post for convenience since (I’m assuming) the majority of people here are in the U.S.

damn!
we get shafted every time we steal from you.

reset trip
There is a Reset Trip option, but it doesn’t reset the max speed or odometer. I have to reset those separately.

i’m going to reinitialize the satellites
I thought losing the signal or dropping a satellite might be the problem but the only thing is, I’ve always been out in the open, paddling in lakes. One of the days was overcast but the other three days were clear skies.



The manual says to re-initialize the satellites whenever the unit is being used in a new state/province or moved several hundred miles so I’ll try that (even though I’m in the same province and the unit hasn’t been further than 200km from where I initialized it the first time.



I’ll try it out this weekend and see what happens.

just gotta love the end of this thread
Heheh, you poor guys to the north, after all you do for us ya still get the short end!

hang in there, I assume Garmin has or will have a patch for your firmware that may resolve your problem…ya shoulda got a Garmin 60Cx

A patch isn’t going to solve his problem
probably got maple syrup in it or something.

Where did ya buy it?
And can u return it,or replace it?



Gotta be defective! I have 4 garmin GPS units,one is a handheld, one is a forerunner.

never seen this problem before with any of them.



Very unusual!!!



P.S. forgot about the garmin street pilot! it’s dead on too.