GPS - Comparison of eTrex and Geko

www.rambler-info.org.uk - comparison of eTrex and Geko

The units compared

I want to compare the two units that I own and use. They are an eTrex Summit and a Geko 201. This is going to mean that I am comparing a unit with a barometric altimeter and a unit without. I have not covered prices since they vary, but the Geko is cheaper.

There is also the issue of whether to buy a unit with an altimeter (eg Geko 301). It seems better to keep this as a separate issue.

The similarities

All the standard operations used by walkers
Ability to download and store data on a computer
Ability to link to mapping software
Size. (Photo is approximately correct)
Ergonomics. Different, but both good.
Both need a clumsy adapter for USB connection.

The differences (click on item for details)

Altimeter or not?

Do you really need an altimeter? Although a GPS is less accurate vertically than horizontally, all the Garmin models give an altitude readout (I think). This GPS altitude does not depend on the weather. The altitude information can be downloaded to your computer.

In contrast the models with a barometric altimeter (like the eTrex Summit) are sensitive enough to pick up differences of 5m in altitude. However they react to weather changes and would then start changing altitude even if kept at a fixed spot.

To overcome this, the manufacturers offer an "Auto-calibrate" setting. This appears to use the difference between the GPS height and the barometric height to calibrate the latter. If this sounds crazy, be reassured that the system only reacts to long-term differences. If you do not calibrate your GPS at the start of a walk then auto-calibrate will take about an hour to complete its task. This can sometimes mean your circular walk appears to end at a different altitude to which it started.

I may by now have convinced you that you do not need a barometric altimeter. You may still be wondering why would anyone buy one? Well, there are some uses...

The eTrex Summit and presumably the Geko 301 will give a readout of total ascent and descent for a walk (in effect totalling up all the rises and falls in a "roller-coaster" walk).
This is useful information for classifying walks by how strenuous people will find them.
[If someone ever writes a piece of software to do this on my computer, then the advantage vanishes.]
If you are coming down off a big mountain in cloud, then you can set the altimeter at the summit or other known point to help you hunt more accurately for critical points in the descent route.

Buying a cheaper model?

There are two cheaper versions of these units: the basic eTrex and the Geko 101 (no longer in production). I would not consider buying either of these, since they cannot be connected to computer to store and retrieve data.

Comment after two years of use

I have now lost my fear of the Geko's short battery life. I use charged-that-morning NiMH batteries for UK use and disposable alkaline batteries for longer days overseas. I am addicted to the light weight and small size of the Geko.

And now,after three years, I have bought a battery charger from BatteryLogic. Everyone should buy one! It is effectively four battery chargers in one. You can mix AA and AAA batteries at different states of charge, you can test your batteries for capacity and eliminate poor ones from a set. It takes over all the tasks a competent NiMH owner could do and does them easily.