The Garmin Fenix 8 Solar - 51mm is a powerhouse designed for endurance athletes, outdoor adventurers, and those who demand top-tier GPS performance and durability. It builds upon its predecessors with improved solar charging, enhanced GPS accuracy, and longer battery life, all while maintaining the rugged and premium build quality that defines the Fenix lineup.
Here at the Outdoor GPS Shop we have sold and used this watch from the day it was launched in August 2024.
Garmin continues to differentiate the MIP (Memory-In-Pixel) display variant from its AMOLED counterparts, ensuring maximum efficiency in sunlight and extending battery life to impressive levels.
If your priority is reliability in extreme environments, superior battery life, and topographical mapping capabilities, the Fenix 8 Solar is an excellent investment.
Performance Comparison
GPS & Sensor Accuracy
The dual-frequency GNSS (Multi-Band GPS) provides exceptional accuracy in all terrains, from dense forests to deep canyons.
In real life testing against a precisely measured 2.8-mile reference route, the Fenix 8 Solar recorded 2.74 miles, showing minimal deviation of just 0.06 miles. This is one of the most accurate performances we’ve seen in a GPS watch.
For heart rate accuracy, we compared it against the Polar chest strap, a gold standard in heart rate measurement. The Fenix 8 Solar maintained a ±1.46 BPM deviation, demonstrating high precision even during high-intensity workouts.
Additionally, the watch includes an ECG sensor, Pulse Ox (SpO2) monitoring, respiration tracking, and advanced HRV analysis, making it a top-tier choice for endurance athletes looking to optimize performance and recovery.
Activity Tracking & Multi-Sport Performance
The Fenix 8 Solar - 51mm is built for serious athletes with its extensive sports modes, tracking everything from running and cycling to mountaineering, skiing, and ultra-endurance events.
Running & Trail Running: The Fenix 8 Solar features advanced running dynamics, including ground contact time, vertical oscillation, stride length, and real-time stamina tracking. For trail runners, turn-by-turn navigation and ClimbPro ascent tracking provide key insights into elevation gains and pacing.
Cycling & Mountain Biking: The watch integrates seamlessly with Garmin Edge GPS units, supports cycling power meters, and includes MTB-specific dynamics such as jump detection, flow rating, and grit score.
Hiking & Mountaineering: With preloaded TOPO maps, next-gen breadcrumb navigation, and detailed route planning, the Fenix 8 Solar is perfect for backcountry adventurers.
Swimming & Triathlon: The 5ATM water resistance, stroke tracking, and open-water GPS mode make it an excellent choice for swimmers and triathletes.
Skiing & Snowboarding: The watch includes preloaded ski maps and avalanche risk alerts.
With over 100 activity profiles, there is no doubt that the Fenix 8 Solar is one of the most versatile multi-sport watches on the market.
Smartwatch Features & Everyday Use
Beyond sports, the Fenix 8 Solar functions as a full-featured smartwatch.
Garmin Pay for contactless payments
Music storage & streaming (Spotify, Amazon Music, Deezer)
Smart notifications (read and reply to texts, take calls when connected to a phone)
Garmin Connect IQ App Store for additional apps & widgets
Garmin’s redesigned UI makes it easier to navigate key insights on sleep tracking, stress monitoring, body battery energy tracking, and recovery time analysis.
Solar Charging & Battery Life
One of the biggest advantages of the Fenix 8 Solar is its outstanding battery performance:
Standard GPS Mode: Up to 66 hours (expandable to 92 hours with solar charging)
Expedition Mode:More than 2 months with solar input
Smartwatch Mode:Up to 30 days per charge
In real-world conditions, we found that with moderate GPS use, solar charging easily extends battery life by 20-30%, making it an ideal watch for ultra-runners and long-distance adventurers.
Rugged Design & Build Quality
The 51mm case size provides a larger display and enhanced durability, featuring:
Sapphire lens (scratch-resistant and ultra-durable)
Titanium case (lightweight yet rugged)
QuickFit bands (easily interchangeable, compatible with older Fenix models)
5ATM water resistance (suitable for swimming, heavy rain, and extreme conditions)
The watch’s built-in LED flashlight is a game-changer for night navigation and emergency situations, making it a unique feature that Garmin continues to perfect.
Navigation & Mapping
Garmin’s top-tier mapping features are one of the standout reasons to invest in the Fenix 8 Solar:
Preloaded TopoActive Maps (Europe, US, and global regions available for download)
Turn-by-Turn Navigation (like a GPS device, but on your wrist)
ClimbPro Ascent Planner (perfect for mountaineering and hiking)
Real-Time Breadcrumb Trail (ensuring you never get lost)
The multi-band GPS ensures precision in remote locations, making it a top choice for expedition-level adventures.
Should You Buy the Garmin Fenix 8 Solar?
If you’re looking for the most durable, feature-packed, and longest-lasting GPS watch on the market, the Garmin Fenix 8 Solar - 51mm is a phenomenal choice.
Who Should Buy It?
✅ Ultra-Runners & Endurance Athletes – Outstanding battery life, multi-band GPS, and real-time stamina tracking. ✅ Hikers, Backpackers & Mountaineers – Topo maps, ClimbPro, weather forecasting, and turn-by-turn navigation. ✅ Cyclists & Triathletes – Power meter compatibility, VO2 max tracking, and interval training support. ✅ Adventurers & Expedition Travelers – Unmatched durability, emergency features, and solar charging capabilities.
Who Might Want to Look Elsewhere?
❌ Casual Athletes – If you don’t need all the advanced features, a Forerunner 965 or Instinct 2X Solar may be a better fit. ❌ Budget-Conscious Users – The Suunto Vertical Titanium Solar offers similar battery performance at a lower cost. ❌ Those Who Prefer AMOLED Displays – Consider the Garmin Fenix 8 - 51mm Amoled Sapphire if screen brightness and vibrancy are a priority.
Final Verdict
TheGarmin Fenix 8 Solar - 51mm is arguably the best adventure GPS watch available today. With exceptional GPS accuracy, best-in-class solar battery life, detailed mapping, and rugged durability, it is an outstanding investment for serious athletes and outdoor enthusiasts.
If you want the most reliable GPS watch money can buy, this is it. Highly recommended.
I bought this to replace a Montana 700 on the deck of my sea-kayak. The USB socket was dying, and it’s too heavy really for where i was using it. No physical buttons, just a touch screen, weren't really workable on the sea all the time either. Before the Montana the GPSMAP 66 was what I used at sea. This was the best unit at the time and worked really well. Small screen, light weight, physical buttons, AA batteries that lasted over 3 days. All good really. Soon to go to eBay!
The H1 has big shoes to fill. It does look very capable. The buttons work in a similar way to the 66, so it’s very familiar. The larger screen helps for mapping. But no corner fields as I’d got used to on the Montana. With the touch screen off it’s easy to control and for me the interface needs very little tweaking. Mapping and compass are easy to get to out of the box as it is.
Switching the Compass to CDI and turning routing off makes it work on the sea exactly the same as the 66 and the Montana 👍🏻. I can’t see all that much of the map when I have 4 data fields on display. But I can live with that. The Action button on the side cant be configured to toggle the touch screen, with is a big -ve.
Activity tracks and courses seem to be readily accessible nicely. But saved activities building up over a few days cant be moved into a collection on the device by the H1. I have to do this in Garmin Explorer, which isn’t Garmin’s best ever software tool. I try and stay away from that as much as possible!!
Having different profiles available is good too. I have only 3 : Kayaking, Walking and Driving. Though I wont use it much while walking. I prefer the simplicity of my Fenix for following courses and recording walks. The talky Toaster Map is very good too., much better than the Garmin Topo mapping. Though for real detail I use either a paper map or a selection of mapping on the phone.
The InReach capability I look forward to playing with. I recently bought an InReach Mini 3 Plus which I used on my last paddling trip. This ‘just worked’ sending comms over satellite when we had no mobile signal in the Far Northwest of Scotland. The subscription is now suspended so it really just a replacement for my soon to be eBayed PLB. I wondered if I should get inReach on my next GPS. I decided if I did I could simplify further my kit list. I can easily use the SOS button if I want to while on the sea, so all very +ve I think.
One ‘quirk’ is the spine mount. It can be threaded top and bottom with 12.7mm thin webbing tape, if you can find any! It’s an imperial size, not really sold anywhere I can find. Garmin won’t sell me a few m or more of their tiny tape loop things without a carabiner, a bit -ve in my mind.
I can work around it by threading the slots with Dyneema Paracord so I can fix it to my spray deck well enough I think and detach it at the end of the day to charge, etc.
Overall I am quite pleased with the GPSMAP Hi1 Plus. It will do a great job for what I want. I look forward to seeing exactly how long the battery lasts over a few days use 🙂.
PS … it did get stuck in the endless reboot cycle once 😮. A quick search of youTube revealed a fix involving a long press of the power button to switch it off, then hold down the page and enter buttons at the same time while pressing the power button once. It churned away and fixed itself 👍🏻.
Well worth the Upgrade from the gpsmap 67 if you have the cash. Finally easy to use better screen and ui.
Top service and best price around fron outdoor gps.
Don't get me wrong it's a luxury purchase for me, update from fēnix 7 but it's loverly with great features. Very happy 👍 fast delivery good quality usb c to hdmi included. Recommended seller with good videos on YouTube
Great advice over the phone and super fast delivery. Also purchased all the extras so was able to get out and about as soon as it arrived. Fantastic service.
It dose what it says on the box
It’s absolutely brilliant boiled water in a matter of minutes
And the delivery was exceptional as you can see from the photos it’s blowing a gale up in the Lake District and not once as it blown out
Surprising easy, for Garmin, to setup and pay for registration for the first month.
After 1 month I plan to suspend the monthly subscription and use it only as a PLB replacement most of the time when on day trips. When we do some extended sea-kayaking trips in May and September I can re-enable on the cheapest plan to be able to communicate when there is no mobile signal. This is all very straightforward in the Garmin Messenger app 👍🏻.
(I climb the mountain so I can see the world, not so the world can see me)
Great GPS functionality - locks on quickly.
Suunto coach comes free with the app and has AI training plans, so, you don’t have to subscribe to such things separately.
Battery life is great.
I bought the GPSMAP H1 online but picked it up from the Office in Northumberland as I was on holiday in the area a few days after I ordered it. I spoke with Jon, a really helpful and friendly guy. The staff at the office were good too.
This device is really great. It came with some helpful documentation printed off by the shop. To get the best out of it use Garmin express and Garmin base map on either a Mac or a Windows computer.
However, setting up your own courses on screen is fairly simple too. The preloaded maps are perfectly good, but if you want Ordnance survey maps there's a slot for an SD card. You can switch the touch screen off which is dead handy if you want to keep it in your pack or pocket whilst walking.
The pictures I have attached show a course I did on screen. Also a bearing on the Humber Bridge. Apols for the quality but I needed three hands really.
Overall I'm delighted.
It's a complex thing so if you haven't had one before, take a couple of hours to mess about with it before going out and field test it on a walk you're familiar with.
Bought the H1 GPS with the additional 1.5 maps .
Arrived all checked over with card installed and set up for me. Thanks guys.
Delivery was fast , works great straight out the box and can’t fault the service.
The H1 works great after familiarise myself around the menu options.
Took it out with me, for a test on a local walk. After I’d loaded up a route into it from Garmin explore app. Works great, very impressed with the touch screen feature .
Added a screen protector and silicon soft case, for some extra protection . 😊
I had a Montana before this which was good but this is much better in that it has buttons and it’s more compact.
The service from Outdoor GPS is also worth a mention as they were outstanding.
My daily cycling routine involves 32km, and these Suunto Wing 2 have significantly improved my rides. I enjoy listening to music while staying aware of traffic. The lights are a fantastic feature for evening rides.
They also perform well in strong winds.
Overall, I love them.
Very happy with my purchase!
It comes setting up straight from the box and with lots of useful information and paperwork.
The person who answered on the phone was friendly and helpful.
100% recommend!
Excellent service from start to finish. Very responsive to my questions and clearly knowledgeable about the product. They took the time to explain things properly rather than giving rushed answers, which gave me confidence in the purchase. Delivery was smooth and everything arrived exactly as described. Would definitely use them again.
Lovely large screen to view and so many different activities to track. Excellent analysis after each activity which can be accessed on my phone or iPad and I can compare stats for same routes. Still getting used to all the functions to make the best of everything.
From start to finish I cannot fault Outdoor GPS Shop. Great price and great communication.
I love my watch, it is packed with features and is well made.
I will definitely be back for my next one, though hopefully this will last me a while.
Cheers
Reviewed various GPS units and wanted the extra confidence whilst out solo in the fells to be able to communicate with family. This ticks all the boxes.
Great seller, Great watch. Exactly what i wanted and delivered promptly.
You can't ask for anything more.
All of my friends are asking me about the watch and where i got it from at this heat price.
Very well pleased.
Martin B
Ok piece of kit. But the Spine mount does not seem to latch very securely. I can lift it off very easily. It does not inspire confidence it will stay in place when used in extremis. I will have to use it a few times to see how well it works.
Great service, prompt delivery.
Still getting used to the device but it seems simple enough. Hope I never have to use it in an emergency but knowing it is there is provides reassurance.
I upgraded to this from my previous Garmin MAP67i.
The H1 is very good, although a little heavier. It’s a shame Garmin have chosen to remove the nice bold/ wide magenta line on courses that I plot. The thinner course line with the arrows is fine but not great in poor conditions.
It only now seems to be available using tracback.
For some reason the satellite is still much slower than using the explorer app on the phone, which is problematic in storms (having recently returned from a Norwegian expedition).
Irritatingly the screen often zoomed out of the course resulting in difficulty reverting to it again.
Garmin still have a lot of work to do and I still find it clunky despite the touch screen improvements and convoluted and laborious processes involved to find things. Good to see they have removed the ludicrous routes & tracks thing and can just focus on a created course.
But I really do hope Garmin reintroduce the previous wide magenta line function on the next software update.
I go to some of the remotest places on the planet so this would be appreciated.
