GPS Tracks

There have been many posts on this site asking for GPS recommendations and I have read most of them. None seem to address GPS resolution and track accuracy.

Previously, I’ve used a Palm Treo with a BlueTooth GPS. This combination was nearly perfect for recording GPS tracks. The GPS resolution was ~1.5 meters, the noise was quite low, and it worked fine even when buried in a dry box in the day hatch. With the phone function turned off, I had no problems with batter life. I could record tracks for more than 16 hours between battery recharges.

I replaced the Treo with an iPhone, but GPS just doesn’t cut it. It barely works when I hold the phone above my head while standing within site of two cell towers. And the battery life stinks (even in airplane mode). I think I just need to finally get a real GPS.

I don’t really care about mapping or whether or not it floats. I care about telling it to “record my track”, sticking it in a drybox, and then have it still recording when I stop paddling at the end of the day. I also want the tracks to be fairly accurate (~3M resolution or better). Support for exporting to GPX format would be nice as well.

If anyone has any experience with this and can reccomend a GPS unit, I would greatly appreciate it.

Most GPS units will do that.
A 100 dollar etrex works just fine with tracking. Never had any issue with it. Due to the way the GPS system is set up unless you have a military or avionics unit you are not going to get much better accuracy than a few meters.

No they won’t

– Last Updated: May-16-09 8:54 AM EST –

Most need a clear view of the sky.
Many will lose satellite reception just going under a thick tree canopy and will definately lose it going under a long bridge.
From experience with several different models.

Jack L

Depends on what you put them in
My eTrex Vista works just fine inside the dayhatch of my glass kayaks, and it’s in a drybag to boot. Works on the dashboard of my car, too.

Heavy tree cover does mess with it, and staying under bridges for more than a few moments will as well. But overall, I’m happy with how it works.

I agree with Seadart
For kayaking, particularly for activities like sea kayaking, a basic GPS would work fine. I have a Garmin Foretrex I use for this type of thing (and it cost about $100 when I got it). I keep it in a translucent dry bag on my deck, and that doesn’t seem to affect the signal.

On the plus side, it does also give basic info you might like while you are paddling, such as speed, distance covered, time of day, etc.

If you go in canyons, you will likely lose signal. A GPS with the SERF chipset would be better in these situations, but these are more expensive.

Newer in Garmin Units
The newer Garmin units might get reception inside a closed hatch. Any Garmin with an H or X in the model name. Venture HC, Vista HCX, Legend H, eTrex H, 60CSX, 76CSX, etc. all have high sensitivity receivers.

I get reception with my 60CSX in my basement with 2 tiny windows, as well as buried in my pack, so it might work inside a kayak hatch, though a deck mount is probably the best bet. The H models are a notch below the 60CSX reception wise but still quite good.

For what you want the basic eTrex H (around $89) will do the job, but it doesn’t come with a PC cable and uses an serial port. By the time you buy the cable and USB adapter (assuming your PC doesn’t have a serial port) you’re paying another $60 bucks or so.

So you can save money by buying a more expensive unit. The Garmin Venture HC runs about $120 and comes with a USB port and cable included in the price. And should you choose to load maps later, it has the capability.

GPS in day hatch
We have a Garmin and a Magellan, the latter lives in a dry bag in my day hatch like Wayne’s. I’ve never had a problem with it keeping a track in open water (not much of a tree canopy on the ocean).

Almost …
Garmin is definitely my favorite.

I think the Garmin eTrex naming codes are:

H = High Sensitivity

C = Color

x = Expandable Memory

I have one of the original GPSMap 60C’s and I like everything about it EXCEPT its lack of sensitivity. A friend of mine has a newer eTrex Legend HCx and even though mine has the big external antenna, the Legend HCx gets MUCH better reception in tree covered areas and canyons.

If I were getting an eTrex series unit I wouldn’t even think about buying another unit that didn’t include “H” in the name, of “C” for that matter.

I don’t think they even make them in the non “H” versions anymore but I’m sure they are still in store inventory out there.


iphone 3G
Are you using the first iPhone or the latest 3G model.

When using GPS Motion X application it performs as good as my Garmin 76S unit. As Celia says, not much tree cover and bridges where we paddle.

The latest Garmin units do have allegedly better reception and faster processors resulting in more accuracy and less loss of satellites.

iPhone 3G
It is an iPhone 3G. The previous model doesn’t have GPS at all.

I’ve tried various apps for the phone and they all seem to work fine. The limitation seems to be the GPS receiver itself. I’m leaning towards just waiting until the 3.0 software comes out. I’ve read contradictory statements, but it’s possible that the bluetooth stack will support serial devices which would allow external bluetooth GPS units to be used.


– Last Updated: May-21-09 9:10 PM EST –

You are correct to a point. The H, C and X designations you noted apply to most units. However the Map 60CSX, Map 76CSX, Oregon and Colorado also have high sensitivity receivers and they don't have the H designation.

In fact the Map 60C(S)X and 76C(S)X units use the SiRF Star III chip set which is the most sensitive chip set available for consumer grade hand helds. The eTrex H units use the cheaper and slightly less sensitive MediaTek chipset and the Colorado and Oregon use the Cartesio chipset which also doesn't perform quite as well as the SiRF Star III chip set in the 60C(S)X and 76C(S)X.

Also, the Map 60CSX, 60CX, 76CSX and 76CX are not to be confused with the Map 60CS, 60C, 76CS and 76C. The latter are older units and do not have a high sensitivity receiver.

Garmin Forerunner 305

– Last Updated: May-22-09 9:10 AM EST –

That's the simplest and smallest paddling GPS you can get. It gives you a heart rate monitor, which is a must if you are doing any sort of controlled training or equipment evaluaiton. Just don't wear it, strap it to the deck or keep in a hatch.

An example of how I use it - here:

Pretty rugged and does not necessarily need a dry box:

A review is available on and compares it with the 405 model (which is not as good as the 305 for kayaking by most indications). There is also a slightly larger 305 version with larger screen and probably more functions for mapping ($179 at Costco). The 305 should be about $150+ with the HR monitor included.

It is also optimized for slow speeds so the tracks it produces are good for kayaking. It also has basic navigation that can be helpful in all else fails and can store way points that you pick.

But primarily, it is a GPS-enabled training device that produces nice traces...

If you want a more interactive GPS to work more than occasionally with the way points along the way, I'd look for something else though.

Accuracy in open areas is very good, perhaps approaching your 3m criteria but not 100% of the time (nothing comsumer-grade does!). Under bridges it gives erratic readings but otherwise is reliable.

Exports the readings to Google Earth so you can do with them what you want I suppose. The Garmin Training Center that is inclued is also useful to analyze your track in terms of plotting various statistics.