First Impressions
Unboxing the Garmin fēnix 8, the first thing that strikes you is that Garmin premium build quality. The watch feels substantial without being bulky, and the AMOLED touchscreen display is absolutely stunning.
Going from button-only navigation to include touchscreen functionality feels natural, and is a transition that Garmin seems to be making across the board with their watches. For scuba diving you do need to rely on the buttons, since touchscreen doesn’t work underwater.
The fēnix 8 is available in 43 mm, 47 mm, and 51 mm. We dove with a 47 mm so we could compare it to our larger Garmin Descent Mk3i and the smaller G1.
Single-Gas Simplicity
If you are considering the Garmin fēnix 8 because you’ve heard great things about the Descent Mk3i or G2, be warned. Those are dive computers first, whereas with the fēnix 8 diving is possible but not the primary focus. We get the impression that because the fēnix 8 pressure sensor works to 130 feet (40 m), Garmin decided scuba would be a nice value-add. And, for many recreational divers, this will work very well.
The fēnix 8’s single-gas dive mode covers the basics for recreational diving. The Garmin interface is clean and intuitive, displaying current depth, dive time, no-decompression limits, and ascent rate warnings.
When compared with the Mk3i, the display was the same—the main difference being that the fēnix is not transmitter-compatible so air integration is not possible.
The fēnix will cover recreational diving scenarios, but advanced divers accustomed to multi-gas planning and deep dives will find the limitations apparent.
Apnea Features
The dedicated apnea mode caters to freedivers and spearfishers, tracking surface intervals, dive times, and maximum depths with precision. The watch can alert you to preset surface intervals, helping maintain safe freediving practices.
This feature set rivals dedicated freediving watches, making the fēnix 8 an excellent choice for divers who split time between scuba and freediving.
Battery Life
One of the fēnix 8’s most impressive features is its exceptional battery life of up to 29 days in smartwatch mode. We did reach out to Garmin to ask what the battery life is from the fēnix 8 in dive mode since it is not stated in the manual. I was told to expect 81 hours for the 47 mm, as diving could be understood as “Max. battery GPS mode.” So of course we placed our fēnix in our mini pressure chamber to check how long it could last.
Staying at a constant depth of 20 feet (6 m) with the display at max brightness, the fēnix lasted 46 hours. I took the fēnix on a week-long liveaboard trip, doing 15 dives in total.
Starting at 100%, the fēnix just made it to the end of the trip with 11% remaining, whereas I did have to charge the Mk3i halfway through the trip. Though bear in mind, the Mk3i is my primary watch so it was doing additional health and sleep tracking and connected to a transmitter underwater.From this, I would deduce thatif you had around 30% battery, and decided on whim to go a dive or two during your vacation, you could rely on it to keep you safe. On a longer liveaboard trip, I would pack a charger to top it up for peace of mind. Considering the brain power of the fēnix, I was impressed with its battery life.
Strap Options
Garmin offers multiple strap options, but for diving, the standard silicone strap performs best. It’s comfortable, quick-drying, and resistant to saltwater damage.
Comparisons
fēnix 8 vs Mk3i
Looks-wise, the fēnix 8 is very similar to the Mk3i, and in a lot of other ways as well.
→ Sports watch: They both perform the same 100-plus activities and collect a plethora of training, planning and analysis features. There are a few minor differences, but nothing that puts one ahead of the other.
→ Smartwatch: Here the fēnix 8 shines. It has a microphone so you can answer calls and reply to messages directly through the watch, and use the voice command for other apps as well.
→ Dive computer: The Mk3i is the dedicated diving workhorse with its 660-foot (200 m) depth rating, air-integration capabilities, diver-to-diver messaging, and comprehensive technical dive modes. It’s built specifically for serious divers who want the most advanced underwater features available.
fēnix 8 vs Apple Watch Ultra
The Apple Watch Ultra is perhaps the fēnix 8’s most direct competitor when it comes to diving. Both target active users who want diving capability without compromising everyday functionality.
→ Sports watch: The Ultra covers most common activities, but the fēnix 8’s 100-plus activity profiles and deeper training analytics give it the edge for serious athletes.
→ Smartwatch: The Ultra dominates here. A superior app ecosystem, more intuitive interface, Siri voice commands, and seamless iPhone integration make daily interaction more fluid than the fēnix 8.
→ Dive computer: Both handle recreational diving adequately with the same recreational 130 feet (40 m) depth ratings. Battery wise, the Apple Watch Ultra lasted 12 hours in dive mode, and whereas the fēnix 8’s excelled with 46 hours.
fēnix 8 vs Suunto Ocean
The Suunto Ocean presents an interesting alternative that bridges dedicated dive computers and smartwatches. Both offer similar recreational diving capabilities, but their approaches differ significantly.
→ Sports watch: The fēnix 8 definitely wins here with its 100-plus activity profiles and advanced training metrics. Comparatively, the Ocean covers basic fitness tracking and lacks the depth of Garmin’s training ecosystem and long-term health insights.
→ Smartwatch: Neither excels here, but the fēnix 8’s microphone, voice commands, and better notification handling give it a slight edge.
→ Dive computer: The Ocean has a deeper limit of 197 feet (60 m), has a gauge mode, and can handle 5 gases. Battery in the dive mode were also similar. The Ocean reached an impressive 52 hours, and the fēnix reached 46 hours.
Price/Quality Ratio
The fēnix 8 sits at the premium end of both smartwatch and dive computer markets. While expensive compared to basic dive computers, the value proposition becomes clearer when considering all its impressive features.
Compared to buying separate devices—a premium smartwatch plus a recreational dive computer—the fēnix 8 offers competitive value while eliminating the need to manage multiple devices.
Do we recommend the Garmin fēnix 8?
Yes, but with important caveats. The fēnix 8 excels as an all-in-one solution for recreational divers who want comprehensive fitness tracking and basic diving functionality in a premium package. However, technical divers requiring air integration or budget-conscious buyers should look elsewhere.
Specs & Features
| Display type | AMOLED |
|---|---|
| Display size | 43, 47 & 51 mm |
| Screen resolution | 454 x 454 pixels |
| Battery | Rechargeable; smartwatch up to 29 days |
| Size | 51 x 51 x 14.7 mm |
| Depth rating | 130 feet (40 m) |
| Number of gases | 1 |
| Dive modes | Single-gas, apnea, nitrox |
| Alarms | Vibration only |
| Dive log capabilities | Sync via Garmin Dive App |
| Transmitter compatible | No |
| Weight | Stainless steel: 102 g (case only: 74 g); Titanium: 92 g (case only: 64 g) |
| Number of buttons | 5 |
| Compass | Yes |
| Wrist straps | Multiple including silicone |
Take a moment to look at this.
