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Casio GW9400-1 Review

A classic ABC watch with impressive battery life
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casio gw9400-1 altimeter watch review
Credit: Casio
Price:  $300 List
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Manufacturer:   Casio
By Paige Klugherz ⋅ Review Editor  ⋅  Nov 19, 2019

Our Verdict

The Casio GW9400 is the utilitarian watch you picture your hardcore, outdoor-enthusiast dad wearing. It's a rugged altimeter watch with a great battery life but is bulky, can be uncomfortable, and has a cluttered watch face. Along with an altimeter, barometer, and compass, it also features basic timekeeping functions, sunrise/sunset data, and a thermometer. Its aesthetics make it not a watch you're likely to wear in your everyday life unless you're a backcountry guide or ranger, and for a similar price, you could find another watch with additional features such as GPS tracking. However, if durability and longevity are your biggest needs, this could be one to consider.
REASONS TO BUY
Durable
Long battery life
REASONS TO AVOID
Very bulky
Lots of buttons
Busy display
Not intuitive

Our Analysis and Test Results

This watch is a winner when it comes to battery life and has some good basic features, but it's uncomfortable and visually overwhelming.

Performance Comparison


casio gw9400-1 altimeter watch review - taking an altitude reading.
Taking an altitude reading.
Credit: Paige Klugherz

Altimeter Accuracy


This watch takes altitude readings based on barometric pressure, which works because generally air pressure decreases as you go higher. However, the drawback of this method is that barometric pressure can change with weather, meaning that if a storm rolls in, your altimeter may give you an inaccurate reading. The user manual even recommends calibrating your altimeter based on a known elevation as frequently as possible to help account for this.

We found that the altimeter was decently accurate- not great, not terrible. When calibrated at a trailhead right before a hike, it would do pretty well. One evening after being calibrated in Bishop before driving up to Mammoth, its reading was 320' off compared to an elevation sign, which seemed like a significant amount for an hour after calibration.

casio gw9400-1 altimeter watch review - reading 320' lower than the actual elevation.
Reading 320' lower than the actual elevation.
Credit: Paige Klugherz

Battery Life


Battery life is where the Casio watches excel. Relying on a long-lasting rechargeable solar battery means that if you're embarking on a multi-month long trek, you'll never need to worry about access to electricity in order to keep this watch working. Its specs claim it can go as long as 7 months before needing any exposure to sunlight to charge it, and while we weren't able to spend a winter in the Arctic to verify this, we believe it. Throughout testing, which involved both weeks of use as well as weeks in a desk drawer, it stayed at the medium or high battery levels. You won't ever need to go out of your way to charge this watch, since general exposure to sunlight while on your wrist should be enough to keep it fully functioning.

casio gw9400-1 altimeter watch review - after months of use without going out of our way to make sure it...
After months of use without going out of our way to make sure it gets sunlight, the battery is still sitting at half-full (M).
Credit: Paige Klugherz

User Experience


In spite of its fairly conservative number of features, this is one watch that you'll definitely need to sit down and read the manual for. Similar to the Suunto Core and Ambit models, it has five buttons (not including a separate backlight button), but we found the GW9400 much more complicated to learn. Each button has multiple labels and functions that can be hard to distinguish because of how they're etched into the black casing. Even setting the time and location required a deep dive into the user manual. The watch face packs a lot into a fairly small screen, and we didn't like how cluttered it felt.

The backlight was bright enough, but it only stayed on for one second at a time with no option to hold it in and keep it on, which could prove frustrating if trying to change or view a setting during the night. Frustration was the general mood when using this watch- a lot of the actual functionality is just more complicated than it needs to be.

casio gw9400-1 altimeter watch review - the five buttons and sensor of the 9400, not including the light...
The five buttons and sensor of the 9400, not including the light button on top below the watch face.
Credit: Paige Klugherz

Fit


Watches don't get bulkier than this one. It's a behemoth on your arm, and for our small-wristed reviewers, it was impossible to get a comfortable fit. Measuring the watch face down the length of your arm, the diameter is 52 mm, but measuring the face from one side of your arm to the other, the diameter is 65 mm. This is due to the straps being inflexible where they join the main watch body, so on a smaller arm, there's a lot of extra space where it can't be tightened down.

The screen itself is 30 mm in diameter, with the part of the screen that's actually showing data measuring closer to 25 mm. This feels a bit disappointing when you consider how much real estate the watch is taking up on your arm. The buttons were responsive, and we didn't have any issues using them with gloves on, but it'd be hard to fit this watch under close-fitting layers.

casio gw9400-1 altimeter watch review - the heavy, bulky casio dug into our testers' arms and was difficult...
The heavy, bulky Casio dug into our testers' arms and was difficult to tighten down.
Credit: Paige Klugherz

Features


Although it has the features you expect in a basic ABC watch, it felt like learning to use them was more complicated than necessary.

Altimeter and Barometer


The altimeter and barometer use a sensor on the left side of the watch, with the altimeter measuring a range of -2,300' to 32,800'. The barometer screen also shows the temperature and a barometric pressure graph of the previous 42 hours from the automatic readings the watch takes every two hours.

Compass


Compass readings are accessed using the same sensor button that gives you altimeter and barometer readings. It can be calibrated, and we found its accuracy on par with the other ABC watches tested. The manual recommends bringing a compass to double-check readings in high-consequence situations.

Timekeeper


Heavy backcountry sleeper? Good news- you can set five daily alarms on this model so that you never miss your predawn wake-up call! (This can be a surprisingly rare feature in altimeter watches.) Other than that, the basic timekeeping features include a stopwatch, timer, world clock, and sunrise/sunset data for your programmed location.

casio gw9400-1 altimeter watch review - jenny (left) wears the gw9400 on an evening run near mammoth lakes...
Jenny (left) wears the GW9400 on an evening run near Mammoth Lakes while testing its features and comfort against other watches.
Credit: Paige Klugherz

Value


The number of customers looking for this specific watch is bound to be small. There are multiple other watches at the same price point that offer either more features, better style, or both. If all you're needing is a basic altimeter watch, and you still want the look and durability of a Casio, we recommend the Casio SGW-300H for about one-fifth the price of this model.

Conclusion


The Casio GW9400 is a basic ABC watch with a steep learning curve. Its battery life is impressive, its aesthetics are not, and unless you're going on the longest and most rugged adventures, it's probably not the watch you're looking for.

casio gw9400-1 altimeter watch review - we took the casio on some big high sierra days and didn't enjoy the...
We took the Casio on some big High Sierra days and didn't enjoy the heaviness and bulk of the watch.
Credit: Paige Klugherz

Paige Klugherz