For those that own an altimeter watch that gives altitude based on GPS readouts, your altitude will be as accurate as the map datum the watch is using to generate altitude. We'll discuss why in a minute. The majority of altimeter watch owners have an altimeter watch that calculates altitude using barometric pressure. In the following paragraphs I'll discuss the difference between GPS and barometric pressure altimeter watches and give examples of each.

GPS altimeter watches use latitude and longitude coordinates to identify your position on the grid and read out an altitude. This data is delivered to the watch from the manufacturer satellite and usually is based on USGS datum. If you have a GPS enabled altimeter watch you never need to recalibrate your watch since the information being displayed comes from a satellite and not from "on ground" conditions. Examples of GPS enable altimeter watches include the Forerunner series from Garmin and the Suunto X10.

Almost every non-GPS altimeter watch on the market uses barometric pressure to determine altitude. The watch has a function in it's built in software that takes the barometric pressure and calculates altitude. Because of this, the altitude readout accuracy needs to be carefully scrutinized, particularly if the weather has changed significantly since you last calibrated your watch. Examples of barometric pressure altimeter watches are the High Gear Axis and the Suunto Core.  As already discussed, barometric pressure altimeter watches are subject to the outdoor weather conditions and as such should be calibrated at regular intervals.

The price points on GPS and barometric pressure watches are varied, with GPS enabled altimeter watches generally being more expensive. An altimeter watch using barometric pressure (such as the HighGear Axis or Suunto Vector) can be found for as little as $100. The GPS enabled altimeter watches are generally more expensive, with an entry price of around $250.

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Suunto Core Aluminum Black

The Suunto Core was poised to become the next great thing in altimeter watch technology! And initially, the outdoor gear industry was enamored with the Suunto Core and it's vast improvements on existing altimeter watch technology. The feature set promised to revolutionize the industry - with great features like the storm warning the Suunto Core was set to go beyond a data delivery device, and turn itself into a safety watch critical to every outdoor person's gear staple.

However, within a few months of the 2007 product release, early adopters of the Suunto Core started registering significant and repeated complaints. Common issues were low battery life, product casing quality, and firmware malfunctions.  It appeared Suunto had been either premature in it's release of the Suunto Core, or just had not spent enough time testing product quality.

Throughout 2007, 2008 and 2009, Suunto (true to it's reputation as THE leader in the outdoor watch industry) invested considerable capital into fixing existing Core units and remedying the underlying issues. The watch at its core (pun intended) is still a great product and Suunto has stuck to it's guns in keeping this watch on the market and positioning it as the altimeter watch for your outdoor adventures.

Suunto Core Light Green

The great news is that over the last year, the Suunto Core altimeter watch issues have been resolved and when buying one you can almost (nothing is 100%, right) be sure you are getting a great watch that will last for years. The Suunto Core runs from $249 to $499 and is available in Black Yellow ($249), Light Green ($249), Regular Black, All Black Military ($299),  Orange Black ($349), Light Black ($349), Aluminum Black ($499), and Aluminum Light versions.

Technorati Tags: Altimeter Watch, Altimeter Watch Review