Not long ago I got my hands on the ATMOS Mission dive computer, and it just so happened that a friend had picked up the other hot model of the year — the Crest CR4. So I borrowed it for a side-by-side comparison. There is a price difference between the two: the ATMOS Mission retails at NT$13,500, while the Crest CR4 is priced at NT$5,980. They are clearly in different tiers. But since both launched around the same time, I'm sure plenty of people are curious about both.
Appearance
Appearance is fairly subjective — beauty is in the eye of the beholder. Holding both watches, you can immediately tell that the CR4 has more design detail: embossed strap patterns, a matte body finish, a slightly recessed display face (which should reduce the chance of scratching the lens), and a large logo on the caseback. The overall build quality is quite impressive.
Buttons
In terms of button feel, the Crest buttons are softer than the ATMOS buttons. Personally, I prefer the tactile feedback of the ATMOS buttons. Both the ATMOS and the Crest have a button on the left side of the case — the ATMOS places it at the bottom, while the Crest places it at the top. What's interesting is that if you hold the watch in one hand off your wrist, the Crest's button position actually feels more intuitive, sitting right where your index finger naturally falls — almost like pressing a chronograph pusher.
However, once you strap the watch onto your left wrist, you'll find that the ATMOS button placement is actually the more practical choice. Since the watch is worn on the wrist most of the time, the lower-left button ends up sitting right where your right thumb naturally rests.
Beeps and Vibration
The Crest's beep is on the quiet side — in a noisy environment you might not hear it at all. During one dive I didn't notice any audible or vibration alerts from the Crest. The ATMOS is quite loud on land, no complaints there. Underwater, the ATMOS's vibration alert is very noticeable, and because the vibration is so clear, I didn't pay much attention to the sound alerts at all.
Display
The Crest's display looks similar to a calculator-style LCD. After sitting still for a while, the screen goes completely blank and only reappears when you shake it. I imagine the screen blanking is a power-saving measure. The ATMOS, on the other hand, uses a display technology similar to Garmin sports watches — the screen remains visible at all times even without the backlight on. I really appreciate that.
The ATMOS display area is slightly larger than the Crest's, so the information layout feels less cramped. The display resolution also appears higher, with crisper rendering — the Crest's display is noticeably more pixelated by comparison.
Firmware
Firmware is essentially the software running on the watch. I won't compare the decompression algorithms — that's beyond my pay grade as a lowly Advanced Open Water Diver (PADI cert). When it comes to decompression theory, I trust that any reputable dive computer brand knows what they're doing.
Watch Interface
The ATMOS features a fully Traditional Chinese menu interface. A recent firmware update added Japanese and Korean language support on top of the existing Traditional Chinese, Simplified Chinese, and English options. The Crest uses an all-caps English menu, and some parameters are abbreviated due to character length. If you buy the Crest, you'll likely need a bit more time to get used to its interface. That said, a dive computer's core functions are fairly limited, so with a bit of button-pressing, most users should figure out what everything means soon enough.
Dive Alerts
When I bought the ATMOS, the vibration dive alert was the feature I was most excited about. On top of the standard alerts found on any dive computer — no-decompression limit, ascent rate warning, MOD alarm, etc. — the ATMOS also vibrates when the safety stop starts and ends. This means you don't have to stare blankly at your wrist during the safety stop; you can use that time to enjoy the underwater scenery or mess around taking selfies and blowing bubbles with your dive buddy. There are also custom depth and time alerts. For example, if you're conserving air and usually need to head back after about 40 minutes, you can set a time alert to remind yourself — handy for those of us who get lost taking photos and forget to watch the clock. Very practical feature.
Digging through the Crest's menu, I found entries called SDEPTH-THD and STIME-THD, which appear to be the depth and time alert settings. The corresponding xxx-ALM entries are probably toggles to enable or disable those alerts. I didn't notice how these alerts behaved on my last dive, so I'll have to take a closer look next time.
Dive Log Screen
Every dive log entry on the ATMOS can be viewed on the watch with detailed information and a depth profile graph. The presentation is clear and easy to read.
The Crest also displays dive logs on the watch, but the screen is not as clear, and there are some quirks with the fonts — for example, the unit labels °C and m appear extremely thin compared to the other text, which is puzzling. On top of that, given how densely packed the interface is, the label text on the left side of the Crest's log screen is virtually impossible for me to read.
App
As of now, the Crest only has an Android app, so I haven't been able to test it. The ATMOS app is available on both platforms, but it's still fairly basic in terms of features. If you ask me which dive computer app stands out, Deepblu's dive log app is still the best of the bunch. Both teams — keep up the work!
Closing Thoughts
There is a meaningful price gap between these two watches, and naturally that gap is reflected in their feature sets. Beyond the comparisons above, the ATMOS also adds GPS-based dive site functionality and the ability to display smartphone push notifications — features that bring it much closer to what we'd call a modern smartwatch with dive computer capabilities.
The purpose of this article isn't to crown a winner or pick the "best" dive computer. I just happened to have both watches on hand at the same time, so I wanted to share my hands-on impressions and first-hand experience. Given the significant difference in price between the two, I hope this information gives those of you still on the fence something useful to go on.
Extended reading:
