Garmin Descent™ Mk3i – 51 mm vs Garmin fēnix® 8 – 51 mm, AMOLEDSize, Specs & Wrist Fit Compared
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Garmin
Descent™ Mk3i – 51 mm (010-02752-10)
Garmin
fēnix® 8 – 51 mm, AMOLED (010-02905-10)
The Garmin Descent™ Mk3i – 51 mm and Garmin fēnix® 8 – 51 mm, AMOLED share a near-identical 51mm case, so wrist presence comes down to thickness, lug-to-lug and weight.
The Garmin fēnix® 8 – 51 mm, AMOLED is the slimmer of the two (14.7mm vs 16.4mm), so it slides under a cuff more easily.
On the wrist the Garmin Descent™ Mk3i – 51 mm feels lighter (77.8g vs 102g, case only).
Specification Comparison
| Spec | GarminDescent™ Mk3i – 51 mm | Garminfēnix® 8 – 51 mm, AMOLED |
|---|---|---|
| Case Width | 51mm | 51mm |
| Thickness | 16.4mm | 14.7mm |
| Weight | 77.8g | 102g |
| Shape | Circular | Circular |
| GPS | Yes | Yes |
| Display | AMOLED | AMOLED |
| Battery life | Smartwatch: Up to 25 days (10 days always-on) Battery Saver Watch Mode: Up to 31 days GPS Only: Up to 76 hours (56 hours always-on) All Satellite Systems: Up to 55 hours (43 hours always-on) All Satellite Systems + Multi-band: Up to 48 hours (38 hours always-on) All Satellite Systems + Music: Up to 17 hours Max Battery GPS: Up to 118 hours Expedition GPS: Up to 24 days Dive Mode: Up to 66 hours Dive Mode with Air Integration: Up to 40 hours | Smartwatch: Up to 29 days (13 days always-on) Battery Saver Watch Mode: Up to 41 days GPS Only: Up to 84 hours (65 hours always-on) All Satellite Systems: Up to 68 hours (54 hours always-on) All Satellite Systems + Multi-band: Up to 62 hours (49 hours always-on)* All Satellite Systems + Music: Up to 18 hours Max Battery GPS: Up to 145 hours Expedition GPS: Up to 31 days *Assuming typical use with SatIQ technology |
| Battery life (smartwatch mode) | Up to 25 days (10 days always-on) | Up to 29 days (13 days always-on) |
| Battery saver (customizable low power watch) | Yes | Yes |
| Body Battery™ energy monitor | Yes | Yes |
| Power Modes - customizable in-activity battery settings | Yes | Yes |
| Battery type | — | Lithium ion |
| Released | 2023 | 2024 |
Full Specification Comparison
367 specs| Spec | Garmin Descent™ Mk3i – 51 mm | Garmin fēnix® 8 – 51 mm, AMOLED |
|---|---|---|
| Overview | ||
| Family | Garmin | Garmin |
| General | ||
| Battery life | Smartwatch: Up to 25 days (10 days always-on) Battery Saver Watch Mode: Up to 31 days GPS Only: Up to 76 hours (56 hours always-on) All Satellite Systems: Up to 55 hours (43 hours always-on) All Satellite Systems + Multi-band: Up to 48 hours (38 hours always-on) All Satellite Systems + Music: Up to 17 hours Max Battery GPS: Up to 118 hours Expedition GPS: Up to 24 days Dive Mode: Up to 66 hours Dive Mode with Air Integration: Up to 40 hours | Smartwatch: Up to 29 days (13 days always-on) Battery Saver Watch Mode: Up to 41 days GPS Only: Up to 84 hours (65 hours always-on) All Satellite Systems: Up to 68 hours (54 hours always-on) All Satellite Systems + Multi-band: Up to 62 hours (49 hours always-on)* All Satellite Systems + Music: Up to 18 hours Max Battery GPS: Up to 145 hours Expedition GPS: Up to 31 days *Assuming typical use with SatIQ technology |
| Display Size | 1.4” diameter (35.56 mm) | 1.4” (35.56 mm) diameter |
| Case material | fiber-reinforced polymer with titanium rear cover | fiber-reinforced polymer with metal rear cover |
| Color display | Yes | Yes |
| Lens Material | sapphire crystal | Corning® Gorilla® Glass or sapphire crystal |
| Bezel Material | Diamond-like Carbon (DLC) coated titanium | stainless steel or titanium |
| Memory/History | 32 GB | 32 GB |
| Strap material | silicone or DLC coated titanium | silicone |
| Charging method | Garmin proprietary clip charger | Garmin proprietary plug charger |
| Large font option | Yes | Yes |
| Display resolution | 454 x 454 pixels | 454 x 454 pixels |
| Leakproof inductive buttons | Yes | Yes |
| QuickFit® watch band compatible | yes (26 mm) | included (26 mm) |
| Battery type | — | Lithium ion |
| Built-in speaker/microphone | — | Yes |
| Sensors | ||
| GPS | Yes | Yes |
| Compass | Yes | Yes |
| GLONASS | Yes | Yes |
| Galileo | Yes | Yes |
| Gyroscope | Yes | Yes |
| Thermometer | Yes | Yes |
| Depth sensor | Yes | yes (to 40 m) |
| Accelerometer | Yes | Yes |
| SatIQ™ Technology | Yes | Yes |
| Ambient light sensor | Yes | Yes |
| Barometric altimeter | Yes | Yes |
| Pulse Ox Blood Oxygen Saturation Monitor | Yes | Yes |
| Garmin Elevate™ wrist heart rate monitor | Yes | Yes |
| QZSS | — | Yes |
| BeiDou | — | Yes |
| Product Info | ||
| Main SKU | 010-02752-10 | 010-02905-10 |
| Product ID | 852159 | 1228171 |
| Product Name | Descent™ Mk3i – 51 mm | fēnix® 8 – 51 mm, AMOLED |
| Release Date | 11/15/2023 | 8/27/2024 |
| Product Variation | Carbon Gray DLC Titanium with Black Silicone Band | Sapphire, Titanium with Spark Orange/Graphite Silicone Band |
| Clock Features | ||
| Timer | Yes | Yes |
| Stopwatch | Yes | Yes |
| Time/date | Yes | Yes |
| Alarm clock | Yes | Yes |
| GPS Time Sync | Yes | Yes |
| Sunrise/sunset times | Yes | Yes |
| Automatic daylight saving time | Yes | Yes |
| Diving Features | ||
| PO2 | Up to 2.0 with customizable deco PO2 setting | up to 1.6 with customizable Deco settings |
| Tides | Yes | Yes |
| Backlight | yes (configurable time and intensity; auto-on at depth) | yes (configurable intensity; always on) |
| Gas mixes | Air, Nitrox and Trimix, up to 100% O2; 1 bottom gas and up to 11 deco and/or backup gasses. | Air, Nitrox (21-40% Oxygen) |
| APNEA mode | Yes | Yes |
| Deep Stops | yes (using custom gradient factors) | yes (using custom Gradient Factors) |
| Gauge mode | Yes | — |
| Pool APNEA | Yes | — |
| No fly time | Yes | Yes |
| Safety Stop | yes (customizable off/3min/5min) | yes (customizable off/3min/5min) |
| Dive planner | yes (basic NDL + multi-gas deco planner) | yes (Basic NDL & Gas Planner) |
| Multi-gas mode | Yes | — |
| Nitrox support | Yes | Yes |
| Trimix support | Yes | — |
| APNEA hunt mode | Yes | — |
| Air integration | yes (via Subwave™) | — |
| Alerts & alarms | Audible and vibration alarms for ascent rate, PO2, CNS/OTU, NDL, deco, gas switching, tank pressure, gas consumption rate. Customizable (up to 40) audible and/or vibration per dive mode, based on depth or time | yes (vibration only) |
| Single-gas mode | Yes | Yes |
| Gas time remaining | Yes | — |
| Subwave™ Support | Yes | — |
| 3-axis dive compass | yes (with adjustable heading, quick change to 90R, 90L and reciprocal). Indicates degrees and direction back to set heading | yes with adjustable heading, quick change to 90R, 90L, and Reciprocal. Indicates degrees and direction back to set heading. |
| Auto start/end dive | Yes | Yes |
| Decompression model | Bühlmann ZHL-16c with gradient factors | Bühlmann ZHL-16c with Gradient Factors |
| Missed Deco Lockout | yes (can be disabled prior to dive with user acknowledgement) | yes (can be disabled prior to dive with user acknowledgement) |
| Gas consumption rate | Yes | — |
| Custom end-dive timeout | yes (20s to 10 m) | yes (20 sec to 10 min) |
| Custom dive data screens | Yes | — |
| Customizable conservatism | yes (low/medium/high or custom using gradient factors) | yes (Low/Medium/High) |
| Surface diver status widget | yes (surface interval, N2/HE loading, CNS, OTU and tissue compartment status) | yes (Surface Interval, no fly time, N2 loading, CNS, OTU, and Tissue Compartment status) |
| Automatic altitude adjustment | Yes | Yes |
| Residual Tissue Loading Reset | yes (on the surface with user acknowledgement) | — |
| Closed Circuit Rebreather (CCR) | Yes | — |
| Number of transmitters supported | 8 | — |
| Dive ascent/descent rate indicator | Yes | Yes |
| Dive activity maximum operating depth | 200 meters | 40 meters |
| Sync dive log to Garmin Dive™ Mobile app | Yes | Yes |
| Automatically saves dive entry and exit locations | Yes | Yes |
| Gaming Features | ||
| Gaming Activity | Yes | — |
| GameOn™ app compatible | Yes | — |
| Boating Features | ||
| Anchor Alarm | Yes | — |
| Countdown timer | Yes | — |
| Tack assist mode | Yes | — |
| Autopilot Control | Yes | — |
| Boat Data Streaming | CIQ | — |
| Virtual starting line | Yes | — |
| Available Boating Profiles | Boating, Sailing, Sail Racing | — |
| Wearable trolling motor remote | Yes | Yes |
| Built-in barometer and tide tables | yes (downloadable tides) | — |
| Cycling Features | ||
| Courses | Yes | Yes |
| Power guide | Yes | Yes |
| MTB Grit & Flow | Yes | Yes |
| Race an activity | Yes | Yes |
| Power meter compatible | Yes | Yes |
| Advanced cycling dynamics | Yes | Yes |
| Power curve and % FTP workouts | Yes | Yes |
| Compatible with Varia™ lights | Yes | Yes |
| FTP (Functional Threshold Power) | yes (with compatible accessory) | yes (with compatible accessory) |
| Compatible with Varia headlight camera | Yes | Yes |
| Speed and cadence sensor support (w/sensor) | Yes | Yes |
| Cycle Map (routable cycling-specific street map) | Yes | Yes |
| Bike lap and lap maximum power (with power sensor) | Yes | Yes |
| Compatible with Varia™ radar (rear-facing radar) | Yes | Yes |
| Compatible with Vector™ and Rally™ (power meters) | Yes | Yes |
| Compatible with Varia Vision™ (head-mounted display) | Yes | Yes |
| Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories) | Yes | Yes |
| Golfing Features | ||
| PinPointer | Yes | Yes |
| Custom targets | Yes | Yes |
| Tempo Training | Yes | Yes |
| Virtual caddie | Yes | Yes |
| Full vector map | Yes | Yes |
| Handicap scoring | Yes | Yes |
| Tournament legal | Yes | Yes |
| Digital scorecard | Yes | Yes |
| Garmin AutoShot™ | Yes | Yes |
| PlaysLike distance | Yes | Yes |
| Round timer/odometer | Yes | Yes |
| Auto CourseView updates | Yes | Yes |
| Yardage to layups/doglegs | Yes | Yes |
| Hazards and course targets | Yes | Yes |
| Pairs with Garmin Golf app | Yes | Yes |
| Green View with manual pin position | Yes | Yes |
| Preloaded with 43,000 courses worldwide | Yes | Yes |
| Green Contours (with Garmin Golf membership) | Yes | Yes |
| CT10 Automatic club tracking compatible (requires accessory) | Yes | Yes |
| Yardage to F/M/B (distance to front, middle and back of green) | Yes | Yes |
| Stat tracking (strokes, putts per round, greens and fairways hit) | Yes | Yes |
| Wind speed and direction (requires connection to Garmin Golf app) | Yes | Yes |
| Touch-targeting (touch target on display to see the distance to any point) | Yes | Yes |
| Measures shot distance (calculates exact yardage for shots from anywhere on course) | automatic | automatic |
| Swing Tempo | — | Yes |
| Running Features | ||
| Hill score | Yes | Yes |
| Run workouts | Yes | Yes |
| Running power | Yes | Yes |
| Race predictor | Yes | Yes |
| Foot pod capable | Yes | Yes |
| Running dynamics | Yes | Yes |
| Lactate threshold | yes (with compatible accessory) | yes (with compatible accessory) |
| Grade-adjusted pace | Yes | Yes |
| Trail run auto climb | Yes | Yes |
| Performance condition | Yes | Yes |
| Run/Walk/Stand detection | Yes | Yes |
| Stride length (real time) | Yes | Yes |
| PacePro™ Pacing Strategies | Yes | Yes |
| Vertical oscillation and ratio | Yes | Yes |
| Ground contact time and balance | Yes | yes (GCT balance with accessory) |
| GPS-based distance, time and pace | Yes | Yes |
| Course- and weather-specific race predictor | Yes | Yes |
| Cadence (provides real-time number of steps per minute) | Yes | Yes |
| What You'll Love | ||
| Touchscreen | Yes | Yes |
| Display type | AMOLED | AMOLED |
| Water rating | Dive (200 meters) | 10 ATM |
| Garmin Pay™ | Yes | Yes |
| Music storage | Yes | Yes |
| LED flashlight | Yes | Yes |
| Multi-band GPS | Yes | Yes |
| Training status | yes (improved) | Yes |
| Built-in mapping | Yes | Yes |
| Training readiness | Yes | Yes |
| Pulse Ox blood oxygen | Yes | Yes |
| Sleep score and insights | Yes | Yes |
| Battery life (smartwatch mode) | Up to 25 days (10 days always-on) | Up to 29 days (13 days always-on) |
| Garmin ECG App | — | Yes |
| Make calls and send texts via voice | — | Yes |
| Activity Profiles | ||
| Gym | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing, Jump Roping |
| Swim | Pool Swimming, Open Water Swimming | Pool Swimming, Open Water Swimming |
| Cycling | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX |
| Wellness | Walking, Pilates, Yoga, Indoor Walking | Walking, Indoor Walking, Pilates, Yoga |
| Multisport | Swimming/Running, Triathlon | Swimming/Running, Triathlon |
| In the ring | Boxing, Mixed Martial Arts | Boxing, Mixed Martial Arts |
| Team sports | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball |
| Motor sports | Motorcycling, Overlanding, Motocrossing, ATVing, Snowmobiling | Motorcycling, Overlanding, Motocrossing, ATVing, Snowmobiling |
| On the Water | Stand Up Paddleboarding, Rowing, Kayaking, Surfing, Kiteboarding, Windsurfing, Fishing, Boating, Sailing, Sail Racing, Water Skiing, Wakeboarding, Wakesurfing, Tubing, Snorkeling, Sailing Expedition, Whitewater | Stand Up Paddleboarding, Rowing, Kayaking, Surfing, Kiteboarding, Windsurfing, Fishing, Boating, Sailing, Water Skiing, Wakeboarding, Wakesurfing, Tubing, Snorkeling, Whitewater |
| Racket sports | Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball | Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball |
| Snow & winter | Skiing, Snowboarding, Backcountry Snowboarding, XC Classic Skiing, Backcountry Skiing, Ice Skating, Snowshoeing | Skiing, Snowboarding, Backcountry Snowboarding, XC Classic Skiing, XC Skate Skiing, Backcountry Skiing, Ice Skating, Snowshoeing |
| Indoor running | Treadmill Running, Indoor Track Running, Virtual Running | Treadmill Running, Indoor Track Running, Virtual Running |
| Outdoor running | Running, Outdoor Track Running, Trail Running, Ultra Running, Obstacle Racing | Running, Outdoor Track Running, Trail Running, Ultra Running, Obstacle Racing |
| Outdoor recreation | Hiking, Indoor Climbing, Bouldering, Climbing, Hunting, Horseback Riding, Golfing, Disc Golf, Archery | Hiking, Rucking, Indoor Climbing, Bouldering, Climbing, Hunting, Horseback Riding, Golfing, Disc Golf, Archery |
| Other activity profiles | Jumpmaster, Tactical, Inline Skating | Inline Skating |
| Dive | — | Scuba Diving (single gas), Apnea Diving, Depth App |
| Swimming Features | ||
| Pool swim workouts | Yes | Yes |
| Critical swim speed | Yes | Yes |
| Time and distance alerts | Yes | Yes |
| Auto rest (pool swim only) | Yes | Yes |
| Drill logging (pool swim only) | Yes | Yes |
| Pacing alerts (pool swim only) | Yes | Yes |
| Countdown start (pool swim only) | Yes | Yes |
| Underwater wrist-based heart rate | Yes | Yes |
| "Repeat on" rest timer (pool swim only) | Yes | Yes |
| Basic rest timer (up from 0) (pool swim only) | Yes | Yes |
| Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only) | Yes | Yes |
| Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories) | Yes | Yes |
| Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories) | Yes | Yes |
| Heart rate from external HRM (real-time during rests, interval and session stats during rests, and automatic heart rate download post-swim) | yes (with HRM-Tri, HRM-Swim, HRM-Pro or HRM-Pro Plus) | yes (with HRM-Tri, HRM-Swim, HRM-Pro or HRM-Pro Plus) |
| Tactical Features | ||
| Kill switch | Yes | — |
| Stealth Mode | Yes | — |
| Ballistics solver | yes (unlock required) | — |
| Night vision mode | Yes | — |
| XERO™ Locations | Yes | — |
| Dual grid coordinates | Yes | Yes |
| Outdoor Recreation | ||
| Tides | Yes | Yes |
| Up Ahead | Yes | Yes |
| Auto rest | Yes | Yes |
| TracBack® | Yes | Yes |
| Sight 'N Go | Yes | Yes |
| Tide glance | Yes | Yes |
| Back to start | Yes | Yes |
| Fish forecast | Yes | Yes |
| Explore Nearby | Yes | Yes |
| UltraTrac mode | Yes | Yes |
| Vertical speed | Yes | Yes |
| GPS coordinates | Yes | Yes |
| Reference point | Yes | — |
| Area calculation | yes (via Connect IQ™) | yes (via Connect IQ™) |
| Elevation profile | Yes | Yes |
| Projected waypoint | Yes | Yes |
| Total ascent/descent | Yes | Yes |
| Future elevation plot | Yes | Yes |
| NextFork™ navigation | Yes | Yes |
| Distance to destination | Yes | Yes |
| Expedition GPS Activity | Yes | Yes |
| Sun and moon information | Yes | Yes |
| Point-to-point navigation | Yes | Yes |
| Preloaded ski resort maps | Yes | Yes |
| ClimbPro™ Ascent Planner | Yes | Yes |
| Rest Timer (Ultra Run only) | Yes | Yes |
| Preloaded road and trail maps | Yes | yes (Sapphire Editions only) |
| Bread crumb trail in real time | Yes | Yes |
| Downloadable cartography support | Yes | Yes |
| Barometric trend indicator with Storm Alert | Yes | Yes |
| Daily Smart Features | ||
| Stocks | Yes | Yes |
| Calendar | Yes | Yes |
| Connectivity | Bluetooth®, ANT+®, Wi-Fi®, Subwave™ | Bluetooth®, ANT+®, Wi-Fi® |
| Garmin Share | Yes | Yes |
| Find My Phone | Yes | Yes |
| Find My Watch | Yes | Yes |
| VIRB® Remote | Yes | — |
| Morning report | Yes | Yes |
| Red shift mode | Yes | Yes |
| Weather forecasts | Yes | Yes |
| Smart Notifications | Yes | Yes |
| Smart trainer control | Yes | Yes |
| Smartphone compatibility | iPhone®, Android™ | iPhone®, Android™ |
| Controls smartphone music | Yes | Yes |
| On-device Connect IQ™ Store | Yes | Yes |
| Plays and controls watch music | Yes | Yes |
| Find My Phone during GPS activity | Yes | Yes |
| Pairs with Garmin Connect™ Mobile | Yes | Yes |
| Compatible with Garmin Messenger app | Yes | Yes |
| Battery saver (customizable low power watch) | Yes | Yes |
| Realtime settings sync with Garmin Connect™ mobile | Yes | Yes |
| View images from notifications on watch (Android™ only) | Yes | Yes |
| Text response/reject phone call with text (Android™ only) | Yes | Yes |
| Connect IQ™ (downloadable watch faces, data fields and apps) | Yes | Yes |
| Passcode | — | Yes |
| Voice command | — | Yes |
| Bluetooth phone calling and voice assistant support | — | Yes |
| Activity Tracking Features | ||
| TrueUp™ | Yes | Yes |
| Move IQ™ | Yes | Yes |
| Step counter | Yes | Yes |
| Floors climbed | Yes | Yes |
| Calories burned | Yes | Yes |
| Distance traveled | Yes | Yes |
| Intensity minutes | Yes | Yes |
| Automatic rep counting | Yes | Yes |
| Garmin Connect™ Challenges app | yes (optional Connect IQ app) | yes (optional Connect IQ app) |
| Move alerts (displays on device after a period of inactivity) | Yes | Yes |
| Auto goal (learns your activity level and assigns a daily step goal) | Yes | Yes |
| Workout and Training Plans | ||
| HIIT workouts | Yes | Yes |
| Yoga workouts | Yes | Yes |
| Cardio workouts | Yes | Yes |
| Pilates workouts | Yes | Yes |
| Strength workouts | Yes | Yes |
| Garmin Cycling Coach | Yes | Yes |
| Garmin Running Coach | Yes | Yes |
| Garmin Running Coach Experts | Yes | Yes |
| On-screen workout animations | Yes | Yes |
| On-screen workout muscle maps | Yes | Yes |
| Daily Suggested Workout - Cycling | Yes | — |
| Daily Suggested Workout - Running | Yes | — |
| Garmin Coach - Prebuilt Cycling Plans | Yes | Yes |
| Garmin Coach - Strength | — | Yes |
| Daily Suggested Workout - Cycling (Pace and Heart Rate Based) | — | Yes |
| Daily Suggested Workout - Running (Pace and Heart Rate Based) | — | Yes |
| Health & Wellness Monitoring | ||
| Sleep | yes (advanced) | yes (advanced) |
| Hydration | yes (in Garmin Connect™) | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Breathwork | Yes | Yes |
| Fitness age | yes (in app) | Yes |
| Nap detection | Yes | Yes |
| All-day stress | Yes | Yes |
| Women's health | yes (in Garmin Connect™) | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Health snapshot | Yes | Yes |
| Jet lag adviser | Yes | Yes |
| Respiration rate | Yes | Yes |
| Skin temperature | Yes | Yes |
| Resting heart rate | Yes | Yes |
| Abnormal heart rate alerts | yes (high and low) | yes (high and low) |
| Relaxation breathing timer | Yes | Yes |
| Body Battery™ energy monitor | Yes | Yes |
| Wrist-based heart rate (constant, every second) | Yes | Yes |
| Meditation | — | Yes |
| Sleep coach | — | Yes |
| Breathing variations | — | Yes |
| Safety and Tracking Features | ||
| Assistance | Yes | Yes |
| Live Event Sharing | Yes | Yes |
| Incident Detection during select activities | Yes | Yes |
| Incident detection alert on phone for wearables | Yes | Yes |
| Kid Activity Tracking Features | ||
| Toe-to-Toe™ Challenges app | yes (optional Connect IQ Toe-to-Toe™ Challenges app) | — |
| Training, Planning and Analysis Features | ||
| % HRR | Yes | Yes |
| % HR max | Yes | Yes |
| HR zones | Yes | Yes |
| HR alerts | Yes | Yes |
| Shortcuts | Yes | Yes |
| HRV status | Yes | Yes |
| Load ratio | Yes | Yes |
| Manual lap | Yes | Yes |
| Rest timer | Yes | Yes |
| Auto max HR | Yes | Yes |
| Auto scroll | Yes | Yes |
| Finish time | Yes | Yes |
| HR calories | Yes | Yes |
| Voice alerts | Yes | Yes |
| Custom alerts | Yes | Yes |
| Physio TrueUp | Yes | Yes |
| Recovery time | Yes | Yes |
| Training load | Yes | Yes |
| VO2 Max (Run) | Yes | Yes |
| Course guidance | Yes | Yes |
| Endurance score | Yes | Yes |
| Training effect | Yes | Yes |
| Virtual Partner | Yes | Yes |
| Race an Activity | Yes | Yes |
| Realtime stamina | Yes | Yes |
| Advanced workouts | Yes | Yes |
| Interval training | Yes | Yes |
| Race glance/widget | Yes | Yes |
| Training load focus | Yes | Yes |
| VO2 Max (Trail Run) | Yes | Yes |
| Garmin Live Segments | Yes | Yes |
| Strava Live Segments | Yes | Yes |
| GPS speed and distance | Yes | Yes |
| Improved recovery time | Yes | — |
| Configurable lap alerts | Yes | Yes |
| Customizable data pages | Yes | Yes |
| Unified training status | Yes | Yes |
| Touch and/or button lock | Yes | Yes |
| Activity history on watch | Yes | Yes |
| Downloadable training plans | Yes | Yes |
| Training effect (anaerobic) | Yes | Yes |
| Manual multisport activities | Yes | Yes |
| HRM running pace and distance | Yes | Yes |
| Heat and altitude acclimation | Yes | Yes |
| Customizable activity profiles | Yes | Yes |
| Trendline™ Popularity Routing | Yes | Yes |
| Auto Pause® automatic timer halt | Yes | Yes |
| Respiration rate (during exercise) | yes (with compatible accessory) | yes (with compatible accessory) |
| Auto Lap® interval tracking feature | Yes | Yes |
| Primary benefit (Training Effect labels) | Yes | Yes |
| Round-trip course creator (running/cycling) | Yes | Yes |
| Power Modes - customizable in-activity battery settings | Yes | Yes |
| HR broadcast (broadcasts HR data over ANT+® to paired devices) | Yes | Yes |
| Improved interval (includes open repeats, intervals data page, rest screen and auto detection) | Yes | Yes |
| HRV stress test (measures your heart rate variability while standing still, for 3 minutes, to provide you with an estimated stress level; the scale of this is 1 to 100; low scores indicate lower stress levels) | yes (with compatible accessory) | yes (with compatible accessory) |
| Workout benefit | — | Yes |
| Multisport auto transition | — | Yes |
Wrist Fit
Garmin Descent™ Mk3i – 51 mm
Sits best on wrists ~54–73mm wide (≈ 14.4–19.5cm circumference).
Garmin fēnix® 8 – 51 mm, AMOLED
Sits best on wrists ~54–73mm wide (≈ 14.4–19.5cm circumference).
2D Dimension Schematics
Accurate scale drawings based on case dimensions. Drag to pan, Ctrl+scroll to zoom. Works for every watch regardless of photo availability.
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Frequently Asked Questions
Is the Garmin Descent™ Mk3i – 51 mm bigger than the Garmin fēnix® 8 – 51 mm, AMOLED?
Both have a 51mm case. Compare their thickness and lug-to-lug above to judge wrist presence.
Which fits a smaller wrist better, the Garmin Descent™ Mk3i – 51 mm or the Garmin fēnix® 8 – 51 mm, AMOLED?
The Garmin Descent™ Mk3i – 51 mm suits wrists around 54–73mm wide, and the Garmin fēnix® 8 – 51 mm, AMOLED around 54–73mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Garmin Descent™ Mk3i – 51 mm and Garmin fēnix® 8 – 51 mm, AMOLED side by side at true scale?
Yes — the schematics and photos above show both watches at matched scale, and our fit tool overlays each on your wrist width.
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