We tested each watch while running in the high Peruvian mountains and exploring the remote canyons of Utah. We summited several peaks ranging from 9,000 to 16,5000 feet. We wore them through all conditions while comparing each side-by-side. We wore them while working, walking the dog, hiking, and running in the mountains. Each watch has seen it all! Not only did we wear them, but we came up with many objective tests to determine which performed the best. Here are a few tests that we performed to guarantee an objective and accurate review.
To test altimeter accuracy, we calibrated each watch at a common location, hiked uphill, noted the altitude at the summit, then hiked back down again. By doing this, we were able to determine which provided the most accurate readings. We did this several times in a wide range of weather.
To test temperature, we placed each watch on a non-conductive surface to see how their readings compared to that of a classic mercury thermometer. We also performed the same test while wearing the watches on our wrist for 10 minutes.
We tested Battery life via field tests, online surveys, and at-home tests to determine which watches lasted the longest (with and without GPS function). We couldn't test some watches as their estimated battery life is three months, a bit longer than our testing period. We also compared GPS function between each GPS watch and determined which had the most accurate GPS over many days of running the same route and comparing tracks.
We even took the GPS watches into the depths of the Earth (where GPS reception is poor) and determined which watches were best able to keep a GPS lock and provide accurate distance, pace, and altimeter information. To determine the best watch display, we compared reflectiveness in the sun (with and without sunglasses), and also considered the length and brightness of each watch's night light. Finally, for ease of use we simply looked at how easy the watch is to figure out without consulting the users manual.
After performing all these tests, we rated each watch using six different metrics: features, ease-of-use, battery life, altimeter accuracy, display quality, and comfort and fit. After all these in-field and at-home tests, we have produced (what we think) is the best altimeter watch review out there.