Garmin
D2™ Mach 1 Pro vs D2 Mach 2 51mm
Size, specs & wrist fit compared
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Which one fits you
Both need much the same wrist — roughly 54–73mm across the flat of the wrist. Neither will fit where the other won't, so decide on thickness, weight and features instead.
The D2™ Mach 1 Pro and D2 Mach 2 51mm share a near-identical 51mm case, so wrist presence comes down to thickness, lug-to-lug and weight.
On the wrist the D2 Mach 2 51mm feels lighter (92g vs 126g, case only).
The D2™ Mach 1 Pro is middle-of-the-pack for thickness among the 54 51mm watches in the database.
Among the 54 51mm watches we hold thickness for, the D2 Mach 2 51mm is thinner than 94%, so it wears flatter than its width suggests.
The D2™ Mach 1 Pro is 0.3mm thicker and 34g heavier than the D2 Mach 2 51mm. Both are circular.
D2™ Mach 1 Pro
D2 Mach 2 51mm
Case width
51mm
51mmsame
Lug-to-lug
51mm
51mmsame
Thickness
15mm
14.7mm−0.3mm
Weight
126g
92g−34g
Switch or add watches
Garmin
D2™ Mach 1 Pro
Garmin
D2 Mach 2 51mm
Fit tool
Watch Fit Tool
For sports watches, lug-to-lug (L2L) is what matters most — it decides whether a watch overhangs your wrist. Bulky is fine; overhang is not.
Your wrist
mm
≈ 146.9mm aroundDepth
How to Measure Wrist Width
1
Lay your arm flat on a table, palm facing up
2
Measure across the flat top of your wrist (not the circumference)
3
Measure at the point where you wear your watch — typically just below the wrist bone
⚠ Important
Wrist width ≠ circumference. We need the flat width across the top of your wrist where the watch sits, not how far around.
Garmin D2™ Mach 1 Pro
Case 51.0mm · Lug-to-lug 51.0mm · Thickness 15.0mm · 126g
Sweet Spot
51mm on a 55mm wrist
Understated Balanced Sweet Spot Bold Overhang ⚠
Across the wrist it works — 2.0mm spare each side — but a tall watch on this wrist. Fine over a sleeve, awkward under one.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 51mm.
How to Measure
- 1. Lay your arm flat, palm up.
- 2. Measure the flat width across the top of your wrist — not the circumference.
- 3. Measure where you wear it, just below the wrist bone.
Against one you know
Leather: Attaches at the lugs, so the case back rests on your skin. Thins and softens with wear. The default: depth about seven tenths of the width. Typical figures, not this model’s own.
Show the measurementsHide the measurements
- Across the wrist2.0mm spare each side
Fills the wrist without reaching the edge.
- Off the wrist15.0mm off the skin
A tall watch on this wrist. Fine over a sleeve, awkward under one. (15.0mm case, back against the skin)
- How it seats~8.8mm under the rim
Wide enough that the edge of the case back lifts clear of the skin.
- Weight on the wrist126g
Substantial without being a burden — the usual weight of a steel watch on a wrist this size. (2.3g per mm of wrist)
Garmin D2 Mach 2 51mm
Case 51.0mm · Lug-to-lug 51.0mm · Thickness 14.7mm · 92g
Sweet Spot
51mm on a 55mm wrist
Understated Balanced Sweet Spot Bold Overhang ⚠
Across the wrist it works — 2.0mm spare each side — but a tall watch on this wrist. Fine over a sleeve, awkward under one.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 51mm.
How to Measure
- 1. Lay your arm flat, palm up.
- 2. Measure the flat width across the top of your wrist — not the circumference.
- 3. Measure where you wear it, just below the wrist bone.
Against one you know
Leather: Attaches at the lugs, so the case back rests on your skin. Thins and softens with wear. The default: depth about seven tenths of the width. Typical figures, not this model’s own.
Show the measurementsHide the measurements
- Across the wrist2.0mm spare each side
Fills the wrist without reaching the edge.
- Off the wrist14.7mm off the skin
A tall watch on this wrist. Fine over a sleeve, awkward under one. (14.7mm case, back against the skin)
- How it seats~8.8mm under the rim
Wide enough that the edge of the case back lifts clear of the skin.
- Weight on the wrist92g
Substantial without being a burden — the usual weight of a steel watch on a wrist this size. (1.7g per mm of wrist)
2D Dimension Schematics
Every case drawn to scale on a shared centre — from above, and in profile against the wrist.
Highlight
- Garmin D2™ Mach 1 Pro51mm · 15mm thick
- Garmin D2 Mach 2 51mm51mm · 14.7mm thick
3D preview
D2™ Mach 1 Pro vs D2 Mach 2 51mm on a wrist
Sized to your own wrist, turned any way you like.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
Battery life compared
Runtime for every power mode either watch publishes, 1 of them directly comparable.
D2™ Mach 1 ProD2 Mach 2 51mm
Battery Saver Smartwatch
41 days—Expedition GPS
27 days—Smartwatch
25 days26 daysMax battery GPS
145 hours—GPS only
82 hours—All satellite systems
62 hours—Fly activity
46 hours—All satellite systems with multi-band
38 hours—All satellite systems with music
17 hours—
Specifications
The short version
7 key specs| Spec | GarminD2™ Mach 1 Pro | GarminD2 Mach 2 51mm |
|---|---|---|
| Case Width | 51mm | 51mm |
| Thickness | 15mm | 14.7mm |
| Weight | 126g | 92g |
| Shape | Circular | Circular |
| Display type | AMOLED | AMOLED |
| Battery life | Smartwatch mode: Up to 25 days (10 days always-on) Battery Saver Smartwatch mode: Up to 41 days GPS only: Up to 82 hours (58 hours always-on ) All satellite systems: Up to 62 hours (48 hours always-on) All satellite systems with multi-band: Up to 38 hours (30 hours always-on) All satellite systems with music: Up to 17 hours Max battery GPS: Up to 145 hours Expedition GPS: Up to 27 days Fly activity (GPS + SpO2): Up to 46 hours | Smartwatch: Up to 26 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 Fly Activity (GPS + SPO2): 58 hours *Assuming typical use with SatIQ technology |
| Released | 2023 | 2025 |
Every specification
645 specs| Spec | Garmin D2™ Mach 1 Pro | Garmin D2 Mach 2 51mm |
|---|---|---|
| Overview | ||
| Family | Garmin | Garmin |
| General | ||
| Battery life | Smartwatch mode: Up to 25 days (10 days always-on) Battery Saver Smartwatch mode: Up to 41 days GPS only: Up to 82 hours (58 hours always-on ) All satellite systems: Up to 62 hours (48 hours always-on) All satellite systems with multi-band: Up to 38 hours (30 hours always-on) All satellite systems with music: Up to 17 hours Max battery GPS: Up to 145 hours Expedition GPS: Up to 27 days Fly activity (GPS + SpO2): Up to 46 hours | Smartwatch: Up to 26 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 Fly Activity (GPS + SPO2): 58 hours *Assuming typical use with SatIQ technology |
| Display Size | 1.4" (35.56 mm) diameter | 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 | — |
| Bezel Material | titanium | — |
| Memory/History | 32 GB | 32 GB |
| Strap material | Titanium & silicone | titanium and silicone |
| Charging method | Garmin proprietary plug charger | Garmin proprietary plug charger |
| Display resolution | 454 x 454 pixels | 454 x 454 pixels |
| QuickFit® watch band compatible | included (26 mm) | included (26 mm) |
| Weight | — | Titanium: 92 g (case only: 64 g) |
| Battery type | — | Lithium ion |
| Lens material | — | sapphire crystal |
| Physical size | — | 51 x 51 x 14.7 mm Fits wrists with the following circumference: Silicone band: 127-210 mm Metal Band: 135-225 mm |
| Bezel material | — | titanium |
| Large font option | — | Yes |
| Built-in speaker/microphone | — | Yes |
| Leakproof inductive buttons | — | Yes |
| Sensors | ||
| GPS | Yes | — |
| Compass | Yes | — |
| GLONASS | Yes | — |
| Galileo | Yes | — |
| Gyroscope | Yes | — |
| Thermometer | Yes | — |
| Accelerometer | Yes | — |
| SatIQ™ Technology | Yes | — |
| Ambient light sensor | Yes | — |
| Barometric altimeter | Yes | — |
| Pulse Ox Blood Oxygen Saturation Monitor | Yes | — |
| Garmin Elevate™ wrist heart rate monitor | Yes | — |
| Stocks | — | Yes |
| Calendar | — | Yes |
| Passcode | — | Yes |
| Calculator | — | Yes |
| Connectivity | — | Bluetooth®, ANT+®, Wi-Fi® |
| Garmin Share | — | Yes |
| Find My Phone | — | Yes |
| Voice command | — | Yes |
| Evening report | — | Yes |
| Morning report | — | Yes |
| Red shift mode | — | Yes |
| Weather forecasts | — | Yes |
| Smart Notifications | — | Yes |
| Smart trainer control | — | Yes |
| Smartphone compatibility | — | iPhone®, Android™ |
| Controls smartphone music | — | Yes |
| On-device Connect IQ™ Store | — | Yes |
| Plays and controls watch music | — | Yes |
| Find My Phone during GPS activity | — | Yes |
| Pairs with Garmin Connect™ Mobile | — | Yes |
| Compatible with Garmin Messenger app | — | Yes |
| Find My Garmin (helps locate lost device) | — | Yes |
| Battery saver (customizable low power watch) | — | Yes |
| Bluetooth phone calling and voice assistant support | — | Yes |
| Realtime settings sync with Garmin Connect™ mobile | — | Yes |
| View images from notifications on watch (Android™ only) | — | Yes |
| Text response/reject phone call with text (Android™ only) | — | Yes |
| Connect IQ™ (downloadable watch faces, data fields and apps) | — | Yes |
| Product Info | ||
| Main SKU | 010-02804-80 | — |
| Product ID | 1398869 | — |
| Product Name | D2™ Mach 1 Pro | — |
| Release Date | 10/25/2023 | — |
| Product Variation | Aviator Smartwatch with Vented Titanium Bracelet | — |
| Clock Features | ||
| Timer | Yes | — |
| Stopwatch | Yes | — |
| Time/date | Yes | — |
| Alarm clock | Yes | — |
| GPS Time Sync | Yes | — |
| Sunrise/sunset times | Yes | — |
| Automatic daylight saving time | Yes | — |
| Sleep | — | yes (advanced) |
| Hydration | — | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Breathwork | — | Yes |
| Meditation | — | Yes |
| Fitness age | — | Yes |
| Sleep coach | — | Yes |
| Health status | — | Yes |
| Nap detection | — | Yes |
| All-day stress | — | Yes |
| Women's health | — | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Health snapshot | — | Yes |
| Jet lag adviser | — | Yes |
| Sleep alignment | — | Yes |
| Respiration rate | — | Yes |
| Skin temperature | — | Yes |
| Lifestyle logging | — | Yes |
| Resting heart rate | — | Yes |
| Breathing variations | — | Yes |
| Abnormal heart rate alerts | — | yes (high and low) |
| Relaxation breathing timer | — | Yes |
| Body Battery™ energy monitor | — | Yes |
| Heart rate (constant, every second) | — | Yes |
| Gaming Features | ||
| Gaming Activity | Yes | — |
| GameOn™ app compatible | Yes | — |
| PO2 | — | up to 1.6 with customizable Deco settings |
| Tides | — | Yes |
| Backlight | — | yes (configurable intensity; always on) |
| Gas mixes | — | Air, Nitrox (21-40% Oxygen) |
| APNEA mode | — | Yes |
| Deep Stops | — | yes (using custom Gradient Factors) |
| No fly time | — | Yes |
| Safety Stop | — | yes (customizable off/3min/5min) |
| Dive planner | — | yes (Basic NDL & Gas Planner) |
| Nitrox support | — | Yes |
| Single-gas mode | — | Yes |
| Alerts and alarms | — | yes (vibration only) |
| 3-axis dive compass | — | yes with adjustable heading, quick change to 90R, 90L, and Reciprocal. Indicates degrees and direction back to set heading. |
| Auto start/end dive | — | Yes |
| Decompression model | — | Bühlmann ZHL-16c with Gradient Factors |
| Missed Deco Lockout | — | yes (can be disabled prior to dive with user acknowledgement) |
| Custom end-dive timeout | — | yes (20 sec to 10 min) |
| Customizable conservatism | — | yes (Low/Medium/High) |
| Surface diver status widget | — | yes (Surface Interval, no fly time, N2 loading, CNS, OTU, and Tissue Compartment status) |
| Automatic altitude adjustment | — | Yes |
| Dive ascent/descent rate indicator | — | Yes |
| Dive activity maximum operating depth | — | 40 meters |
| Sync dive log to Garmin Dive™ Mobile app | — | Yes |
| Automatically saves dive entry and exit locations | — | Yes |
| Boating Features | ||
| Wearable trolling motor remote | Yes | — |
| TrueUp™ | — | Yes |
| Move IQ™ | — | Yes |
| Step counter | — | Yes |
| Floors climbed | — | Yes |
| Calories burned | — | Yes |
| Distance traveled | — | Yes |
| Intensity minutes | — | Yes |
| Automatic rep counting | — | Yes |
| Garmin Connect™ Challenges app | — | yes (optional Connect IQ app) |
| Move alerts (displays on device after a period of inactivity) | — | Yes |
| Auto goal (learns your activity level and assigns a daily step goal) | — | Yes |
| Cycling Features | ||
| Courses | Yes | — |
| MTB Grit & Flow | Yes | — |
| Race an activity | Yes | — |
| Power meter compatible | Yes | — |
| Advanced cycling dynamics | Yes | — |
| Power curve and % FTP workouts | Yes | — |
| Compatible with Varia™ lights | Yes | — |
| FTP (Functional Threshold Power) | yes (with compatible accessory) | — |
| Compatible with Varia headlight camera | Yes | — |
| Speed and cadence sensor support (w/sensor) | Yes | — |
| Cycle Map (routable cycling-specific street map) | Yes | — |
| Bike lap and lap maximum power (with power sensor) | Yes | — |
| Compatible with Varia™ radar (rear-facing radar) | Yes | — |
| Compatible with Vector™ and Rally™ (power meters) | Yes | — |
| Compatible with Varia Vision™ (head-mounted display) | Yes | — |
| Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories) | Yes | — |
| Pool swim workouts | — | Yes |
| Critical swim speed | — | Yes |
| Time and distance alerts | — | Yes |
| Auto rest (pool swim only) | — | Yes |
| Drill logging (pool swim only) | — | Yes |
| Pacing alerts (pool swim only) | — | Yes |
| Countdown start (pool swim only) | — | Yes |
| Underwater wrist-based heart rate | — | Yes |
| "Repeat on" rest timer (pool swim only) | — | Yes |
| Basic rest timer (up from 0) (pool swim only) | — | Yes |
| Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only) | — | Yes |
| Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories) | — | Yes |
| Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories) | — | 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-Swim, HRM-Pro, HRM-Pro Plus or HRM 600) |
| Golfing Features | ||
| PinPointer | Yes | — |
| Custom targets | Yes | — |
| Tempo Training | Yes | — |
| Virtual caddie | Yes | — |
| Full vector map | Yes | — |
| Handicap scoring | Yes | — |
| Tournament legal | Yes | — |
| Digital scorecard | Yes | — |
| Garmin AutoShot™ | Yes | — |
| PlaysLike distance | Yes | — |
| Round timer/odometer | Yes | — |
| Auto CourseView updates | Yes | — |
| Yardage to layups/doglegs | Yes | — |
| Hazards and course targets | Yes | — |
| Pairs with Garmin Golf app | Yes | — |
| Green View with manual pin position | Yes | — |
| Preloaded with 43,000 courses worldwide | Yes | — |
| Green Contours (with Garmin Golf membership) | Yes | — |
| CT10 Automatic club tracking compatible (requires accessory) | Yes | — |
| Yardage to F/M/B (distance to front, middle and back of green) | Yes | — |
| Stat tracking (strokes, putts per round, greens and fairways hit) | Yes | — |
| Wind speed and direction (requires connection to Garmin Golf app) | Yes | — |
| Touch-targeting (touch target on display to see the distance to any point) | Yes | — |
| Measures shot distance (calculates exact yardage for shots from anywhere on course) | automatic | — |
| Tides | — | Yes |
| Auto rest | — | Yes |
| Sight 'N Go | — | Yes |
| Tide glance | — | Yes |
| Fish forecast | — | Yes |
| UltraTrac mode | — | Yes |
| Vertical speed | — | Yes |
| GPS coordinates | — | Yes |
| Elevation profile | — | Yes |
| Projected waypoint | — | Yes |
| Total ascent/descent | — | Yes |
| Future elevation plot | — | Yes |
| Distance to destination | — | Yes |
| Expedition GPS Activity | — | Yes |
| Sun and moon information | — | Yes |
| Rest Timer (Ultra Run only) | — | Yes |
| Barometric trend indicator with storm alert | — | Yes |
| Running Features | ||
| Hill score | Yes | — |
| Run workouts | Yes | — |
| Running power | Yes | — |
| Race predictor | Yes | — |
| Foot pod capable | Yes | — |
| Running dynamics | Yes | — |
| Lactate threshold | yes (with compatible accessory) | — |
| Grade-adjusted pace | Yes | — |
| Trail run auto climb | Yes | — |
| Performance condition | Yes | — |
| Run/Walk/Stand detection | Yes | — |
| Stride length (real time) | Yes | — |
| PacePro™ Pacing Strategies | Yes | — |
| Vertical oscillation and ratio | Yes | — |
| Ground contact time and balance | yes (GCT balance with accessory) | — |
| GPS-based distance, time and pace | Yes | — |
| Course- and weather-specific race predictor | Yes | — |
| Cadence (provides real-time number of steps per minute) | Yes | — |
| PinPointer | — | Yes |
| Swing Tempo | — | Yes |
| Custom targets | — | Yes |
| Tempo Training | — | Yes |
| Virtual caddie | — | Yes |
| Full vector map | — | Yes |
| Handicap scoring | — | Yes |
| Tournament legal | — | Yes |
| Digital scorecard | — | Yes |
| Garmin AutoShot™ | — | Yes |
| PlaysLike distance | — | Yes |
| Round timer/odometer | — | Yes |
| Auto CourseView updates | — | Yes |
| Yardage to layups/doglegs | — | Yes |
| Hazards and course targets | — | Yes |
| Pairs with Garmin Golf app | — | Yes |
| Green View with manual pin position | — | Yes |
| Preloaded with 43,000 courses worldwide | — | Yes |
| Green Contours (with Garmin Golf membership) | — | Yes |
| CT1 Automatic club tracking compatible (requires accessory) | — | Yes |
| CT10 Automatic club tracking compatible (requires accessory) | — | Yes |
| Yardage to F/M/B (distance to front, middle and back of green) | — | Yes |
| Stat tracking (strokes, putts per round, greens and fairways hit) | — | Yes |
| Wind speed and direction (requires connection to Garmin Golf app) | — | Yes |
| Touch-targeting (touch target on display to see the distance to any point) | — | Yes |
| Measures shot distance (calculates exact yardage for shots from anywhere on course) | — | automatic |
| What You'll Love | ||
| Touchscreen | Yes | Yes |
| Display type | AMOLED | AMOLED |
| Water rating | 10 ATM | 10 ATM |
| Garmin Pay™ | Yes | Yes |
| Music storage | Yes | Yes |
| Garmin ECG App | 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 26 days (13 days always-on) |
| Timer | — | Yes |
| Stopwatch | — | Yes |
| Time/date | — | Yes |
| Alarm clock | — | Yes |
| GPS Time Sync | — | Yes |
| Smart wake alarm | — | Yes |
| Sunrise/sunset times | — | Yes |
| Alarm clock with time zones | — | Yes |
| Automatic daylight saving time | — | Yes |
| Make calls and send texts via voice | — | Yes |
| Activity Profiles | ||
| Gym | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing | — |
| Swim | Pool Swimming, Open Water Swimming | — |
| Cycling | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX | — |
| Wellness | Walking, Pilates, Yoga, Indoor Walking | — |
| Multisport | Swimming/Running, Triathlon | — |
| In the ring | Boxing, Mixed Martial Arts | — |
| Team sports | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball | — |
| Motor sports | 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 | — |
| Racket sports | Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball | — |
| Snow & winter | Skiing, Snowboarding, Backcountry Snowboarding, XC Classic Skiing, Backcountry Skiing, Ice Skating, Snowshoeing | — |
| Indoor running | Treadmill Running, Indoor Track Running, Virtual Running | — |
| Outdoor running | Running, Outdoor Track Running, Trail Running, Ultra Running | — |
| Outdoor recreation | Hiking, Indoor Climbing, Bouldering, Climbing, Hunting, Horseback Riding, Golfing, Disc Golf, Archery | — |
| Other activity profiles | Jumpmaster, Tactical | — |
| Assistance | — | Yes |
| Live Event Sharing | — | Yes |
| Incident Detection during select activities | — | Yes |
| Incident detection alert on phone for wearables | — | Yes |
| Aviation Features | ||
| Aviation Alerts | Yes | — |
| MOS & Meteogram | Yes | — |
| In-flight Pulse Ox | Yes | — |
| NEXRAD on moving map | Yes | — |
| Waypoint information page | Yes | — |
| Density altitude calculator | Yes | — |
| Fly activity emergency mode | Yes | — |
| Connext avionics connectivity | Yes | — |
| Worldwide airport database(s) | Yes | — |
| Multiple time zones with Zulu/UTC | Yes | — |
| TAF (Terminal Aerodrome Forecast) | Yes | — |
| Altimeter with adjustable baro setting | Yes | — |
| METAR (Meteorological Aerodrome Report) | Yes | — |
| Worldwide NAVAID and Intersection database(s) | Yes | — |
| Wirelessly receive flight plans from Garmin Pilot™ | Yes | — |
| 3-axis compass with HSI (horizontal situation indicator) | Yes | — |
| Moving Map with aviation airports, navaids, roads, bodies of water and more | Yes | — |
| Wearable trolling motor remote | — | Yes |
| Swimming Features | ||
| Pool swim workouts | Yes | — |
| Critical swim speed | Yes | — |
| Time and distance alerts | Yes | — |
| Auto rest (pool swim only) | Yes | — |
| Drill logging (pool swim only) | Yes | — |
| Pacing alerts (pool swim only) | Yes | — |
| Countdown start (pool swim only) | Yes | — |
| Underwater wrist-based heart rate | Yes | — |
| "Repeat on" rest timer (pool swim only) | Yes | — |
| Basic rest timer (up from 0) (pool swim only) | Yes | — |
| Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only) | Yes | — |
| Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories) | Yes | — |
| Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories) | 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) | — |
| Tactical Features | ||
| Kill switch | Yes | — |
| Stealth Mode | Yes | — |
| XERO™ Locations | Yes | — |
| Dual grid coordinates | Yes | — |
| Gaming Activity | — | Yes |
| GameOn™ app compatible | — | Yes |
| Outdoor Recreation | ||
| Tides | yes (via Connect IQ™) | — |
| Up Ahead | Yes | Yes |
| Auto rest | Yes | — |
| TracBack® | Yes | Yes |
| Sight 'N Go | Yes | — |
| Tide glance | Yes | — |
| Back to start | Yes | Yes |
| Fish forecast | Yes | — |
| Explore Nearby | Yes | Yes |
| UltraTrac mode | Yes | — |
| Vertical speed | Yes | — |
| GPS coordinates | Yes | — |
| Reference point | Yes | — |
| Area calculation | yes (via Connect IQ™) | — |
| Elevation profile | Yes | — |
| Projected waypoint | Yes | — |
| Total ascent/descent | Yes | — |
| Future elevation plot | Yes | — |
| NextFork™ navigation | Yes | Yes |
| Distance to destination | Yes | — |
| Expedition GPS Activity | Yes | — |
| Sun and moon information | Yes | — |
| Point-to-point navigation | Yes | Yes |
| Preloaded ski resort maps | Yes | Yes |
| ClimbPro™ Ascent Planner | Yes | Yes |
| Rest Timer (Ultra Run only) | 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 | — |
| Daily Smart Features | ||
| Stocks | Yes | — |
| Calendar | Yes | — |
| Connectivity | Bluetooth®, ANT+®, Wi-Fi® | — |
| Garmin Share | Yes | — |
| Find My Phone | Yes | — |
| Find My Watch | Yes | — |
| VIRB® Remote | Yes | — |
| Morning report | Yes | — |
| Red shift mode | Yes | — |
| Weather forecasts | Yes | — |
| Smart Notifications | Yes | — |
| Smart trainer control | Yes | — |
| Smartphone compatibility | iPhone®, Android™ | — |
| Controls smartphone music | Yes | — |
| On-device Connect IQ™ Store | Yes | — |
| Plays and controls watch music | Yes | — |
| Find My Phone during GPS activity | Yes | — |
| Pairs with Garmin Connect™ Mobile | Yes | — |
| Compatible with Garmin Messenger app | Yes | — |
| Battery saver (customizable low power watch) | Yes | — |
| Realtime settings sync with Garmin Connect™ mobile | Yes | — |
| Text response/reject phone call with text (Android™ only) | Yes | — |
| Connect IQ™ (downloadable watch faces, data fields and apps) | Yes | — |
| HIIT workouts | — | Yes |
| Yoga workouts | — | Yes |
| Cardio workouts | — | Yes |
| Pilates workouts | — | Yes |
| Strength workouts | — | Yes |
| Multisport workouts | — | Yes |
| Garmin Cycling Coach | — | Yes |
| Garmin Running Coach | — | Yes |
| Garmin Triathlon Coach | — | Yes |
| Garmin Coach - Strength | — | Yes |
| Garmin Running Coach Experts | — | Yes |
| On-screen workout animations | — | Yes |
| On-screen workout muscle maps | — | Yes |
| Garmin Coach - Prebuilt Cycling Plans | — | Yes |
| Daily Suggested Workout - Cycling (Pace and Heart Rate Based) | — | Yes |
| Daily Suggested Workout - Running (Pace and Heart Rate Based) | — | Yes |
| Activity Tracking Features | ||
| TrueUp™ | Yes | — |
| Move IQ™ | Yes | — |
| Step counter | Yes | — |
| Floors climbed | Yes | — |
| Calories burned | Yes | — |
| Distance traveled | Yes | — |
| Intensity minutes | Yes | — |
| Automatic rep counting | Yes | — |
| Garmin Connect™ Challenges app | yes (optional Connect IQ app) | — |
| Move alerts (displays on device after a period of inactivity) | Yes | — |
| Auto goal (learns your activity level and assigns a daily step goal) | Yes | — |
| % HRR | — | Yes |
| % HR max | — | Yes |
| HR zones | — | Yes |
| HR alerts | — | Yes |
| Shortcuts | — | Yes |
| HRV status | — | Yes |
| Load ratio | — | Yes |
| Manual lap | — | Yes |
| Rest timer | — | Yes |
| Auto max HR | — | Yes |
| Auto scroll | — | Yes |
| Finish time | — | Yes |
| HR calories | — | Yes |
| Voice alerts | — | Yes |
| Custom alerts | — | Yes |
| Physio TrueUp | — | Yes |
| Recovery time | — | Yes |
| Training load | — | Yes |
| VO2 Max (Run) | — | Yes |
| Course guidance | — | Yes |
| Endurance score | — | Yes |
| Training effect | — | Yes |
| Virtual Partner | — | Yes |
| Workout benefit | — | Yes |
| Race an Activity | — | Yes |
| Realtime stamina | — | Yes |
| Advanced workouts | — | Yes |
| Interval training | — | Yes |
| Race glance/widget | — | Yes |
| Training load focus | — | Yes |
| VO2 Max (Trail Run) | — | Yes |
| Garmin Live Segments | — | Yes |
| Strava Live Segments | — | Yes |
| GPS speed and distance | — | Yes |
| Configurable lap alerts | — | Yes |
| Customizable data pages | — | Yes |
| Unified training status | — | Yes |
| Touch and/or button lock | — | Yes |
| Activity history on watch | — | Yes |
| Multisport auto transition | — | Yes |
| Downloadable training plans | — | Yes |
| Training effect (anaerobic) | — | Yes |
| Manual multisport activities | — | Yes |
| HRM running pace and distance | — | Yes |
| Heat and altitude acclimation | — | Yes |
| Customizable activity profiles | — | Yes |
| Trendline™ Popularity Routing | — | Yes |
| Auto Pause® automatic timer halt | — | Yes |
| Respiration rate (during exercise) | — | yes (with compatible accessory) |
| Auto Lap® interval tracking feature | — | Yes |
| Primary benefit (Training Effect labels) | — | Yes |
| Round-trip course creator (running/cycling) | — | Yes |
| Power Modes - customizable in-activity battery settings | — | Yes |
| HR broadcast (broadcasts HR data over ANT+® to paired devices) | — | Yes |
| Improved interval (includes open repeats, intervals data page, rest screen and auto detection) | — | 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) |
| Workout and Training Plans | ||
| HIIT workouts | Yes | — |
| Yoga workouts | Yes | — |
| Cardio workouts | Yes | — |
| Pilates workouts | Yes | — |
| Strength workouts | Yes | — |
| Garmin Cycling Coach | Yes | — |
| Garmin Running Coach | Yes | — |
| Garmin Running Coach Experts | Yes | — |
| On-screen workout animations | Yes | — |
| On-screen workout muscle maps | Yes | — |
| Daily Suggested Workout - Cycling | Yes | — |
| Daily Suggested Workout - Running | Yes | — |
| Garmin Coach - Prebuilt Cycling Plans | Yes | — |
| Gym | — | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing, Jump Roping |
| Dive | — | Scuba Diving (single gas), Apnea Diving, Depth App |
| Swim | — | Pool Swimming, Open Water Swimming |
| Cycling | — | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX |
| Wellness | — | Walking, Indoor Walking, Pilates, Yoga, Mobility |
| Multisport | — | Swimming/Running, Triathlon |
| In the ring | — | Boxing, Mixed Martial Arts |
| Team sports | — | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball |
| Motor sports | — | Motorcycling, Overlanding, Motocrossing, ATVing, Snowmobiling |
| On the water | — | 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 |
| Indoor running | — | Treadmill Running, Indoor Track Running, Virtual Running |
| Outdoor running | — | Running, Outdoor Track Running, Trail Running, Ultra Running, Obstacle Racing |
| Snow and winter | — | Skiing, Snowboarding, Backcountry Snowboarding, XC Classic Skiing, XC Skate Skiing, Backcountry Skiing, Ice Skating, Snowshoeing |
| Outdoor recreation | — | Hiking, Rucking, Indoor Climbing, Bouldering, Mountaineering, Hunting, Horseback Riding, Golfing, Disc Golf, Archery |
| Other activity profiles | — | Inline Skating |
| Health & Wellness Monitoring | ||
| Sleep | yes (advanced) | — |
| Hydration | yes (in Garmin Connect™ and optional Connect IQ™ widget) | — |
| Breathwork | Yes | — |
| Fitness age | yes (in app) | — |
| All-day stress | Yes | — |
| Women's health | yes (in Garmin Connect™ and optional Connect IQ™ widget) | — |
| Health snapshot | Yes | — |
| Jet lag adviser | Yes | — |
| Respiration rate | Yes | — |
| Resting heart rate | Yes | — |
| Breathing variations | Yes | — |
| Abnormal heart rate alerts | yes (high and low) | — |
| Relaxation breathing timer | Yes | — |
| Body Battery™ energy monitor | Yes | — |
| Wrist-based heart rate (constant, every second) | Yes | — |
| GPS | — | Yes |
| QZSS | — | Yes |
| BeiDou | — | Yes |
| Compass | — | Yes |
| GLONASS | — | Yes |
| Galileo | — | Yes |
| Gyroscope | — | Yes |
| Thermometer | — | Yes |
| Depth sensor | — | yes (to 40 m) |
| Accelerometer | — | Yes |
| SatIQ™ Technology | — | Yes |
| Ambient light sensor | — | Yes |
| Barometric altimeter | — | Yes |
| Pulse Ox Blood Oxygen Saturation Monitor | — | Yes |
| Garmin Elevate™ wrist heart rate monitor | — | Yes |
| Safety and Tracking Features | ||
| Assistance | Yes | — |
| Live Event Sharing | Yes | — |
| Incident Detection during select activities | Yes | — |
| Incident detection alert on phone for wearables | Yes | — |
| Kill switch | — | Yes |
| Stealth mode | — | Yes |
| Ballistics solver | — | Yes |
| Night vision mode | — | Yes |
| Dual grid coordinates | — | 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 | — |
| % HR max | Yes | — |
| HR zones | Yes | — |
| HR alerts | Yes | — |
| Shortcuts | Yes | — |
| HRV status | Yes | — |
| Load ratio | Yes | — |
| Manual lap | Yes | — |
| Rest timer | Yes | — |
| Auto max HR | Yes | — |
| Auto scroll | Yes | — |
| Finish time | Yes | — |
| HR calories | Yes | — |
| Voice alerts | Yes | — |
| Custom alerts | Yes | — |
| Physio TrueUp | Yes | — |
| Recovery time | Yes | — |
| Training load | Yes | — |
| VO2 Max (Run) | Yes | — |
| Course guidance | Yes | — |
| Endurance score | Yes | — |
| Training effect | Yes | — |
| Virtual Partner | Yes | — |
| Race an Activity | Yes | — |
| Realtime stamina | Yes | — |
| Advanced workouts | Yes | — |
| Interval training | Yes | — |
| Race glance/widget | Yes | — |
| Training load focus | Yes | — |
| VO2 Max (Trail Run) | Yes | — |
| Garmin Live Segments | Yes | — |
| Strava Live Segments | Yes | — |
| GPS speed and distance | Yes | — |
| Improved recovery time | Yes | — |
| Configurable lap alerts | Yes | — |
| Customizable data pages | Yes | — |
| Unified training status | Yes | — |
| Touch and/or button lock | Yes | — |
| Activity history on watch | Yes | — |
| Downloadable training plans | Yes | — |
| Training effect (anaerobic) | Yes | — |
| Manual multisport activities | Yes | — |
| HRM running pace and distance | Yes | — |
| Heat and altitude acclimation | Yes | — |
| Customizable activity profiles | Yes | — |
| Trendline™ Popularity Routing | Yes | — |
| Auto Pause® automatic timer halt | Yes | — |
| Respiration rate (during exercise) | yes (with compatible accessory) | — |
| Auto Lap® interval tracking feature | Yes | — |
| Primary benefit (Training Effect labels) | Yes | — |
| Round-trip course creator (running/cycling) | Yes | — |
| Power Modes - customizable in-activity battery settings | Yes | — |
| HR broadcast (broadcasts HR data over ANT+® to paired devices) | Yes | — |
| Improved interval (includes open repeats, intervals data page, rest screen and auto detection) | 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) | — |
| Hill score | — | Yes |
| Run workouts | — | Yes |
| Running power | — | Yes |
| Race predictor | — | Yes |
| Running Economy | — | yes (with compatible accessory) |
| Step speed loss | — | yes (with compatible accessory) |
| Foot pod capable | — | Yes |
| Running dynamics | — | Yes |
| Lactate threshold | — | yes (with compatible accessory) |
| Running Tolerance | — | Yes |
| Grade-adjusted pace | — | Yes |
| Trail run auto climb | — | Yes |
| Performance condition | — | Yes |
| Run/Walk/Stand detection | — | Yes |
| Stride length (real time) | — | Yes |
| PacePro™ Pacing Strategies | — | Yes |
| Projected race time and pace | — | Yes |
| Vertical oscillation and ratio | — | Yes |
| Ground contact time and balance | — | yes (GCT balance with accessory) |
| GPS-based distance, time and pace | — | Yes |
| Course- and weather-specific race predictor | — | Yes |
| Cadence (provides real-time number of steps per minute) | — | Yes |
| Variant | ||
| Color | — | Carbon Gray DLC Titanium with Vented Titanium Bracelet |
| Version | — | D2 Mach 2 |
| Case Size | — | 51 mm |
| Solar Charging | — | No |
| Diving Features | ||
| Aviation Alerts | — | Yes |
| Personal minimums | — | Yes |
| In-flight Pulse Ox | — | Yes |
| NEXRAD on moving map | — | Yes |
| Connext avionics connectivity | — | Yes |
| Worldwide airport database(s) | — | Yes |
| Multiple time zones with Zulu/UTC | — | Yes |
| TAF (Terminal Aerodrome Forecast) | — | Yes |
| Altimeter with adjustable baro setting | — | Yes |
| METAR (Meteorological Aerodrome Report) | — | Yes |
| Worldwide NAVAID and Intersection database(s) | — | Yes |
| Wirelessly receive flight plans from Garmin Pilot™ | — | Yes |
| 3-axis compass with HSI (horizontal situation indicator) | — | Yes |
| Moving Map with aviation airports, navaids, roads, bodies of water and more | — | Yes |
| Mapping & Navigation | ||
| Courses | — | Yes |
| Power guide | — | Yes |
| MTB Grit & Flow | — | Yes |
| Race an activity | — | Yes |
| Power meter compatible | — | Yes |
| Advanced cycling dynamics | — | Yes |
| Power curve and % FTP workouts | — | Yes |
| Compatible with Varia™ lights | — | Yes |
| FTP (Functional Threshold Power) | — | yes (with compatible accessory) |
| Compatible with Varia headlight camera | — | Yes |
| Speed and cadence sensor support (w/sensor) | — | Yes |
| Cycle Map (routable cycling-specific street map) | — | Yes |
| Bike lap and lap maximum power (with power sensor) | — | Yes |
| Compatible with Varia™ radar (rear-facing radar) | — | Yes |
| Compatible with Vector™ and Rally™ (power meters) | — | Yes |
| Compatible with Varia Vision™ (head-mounted display) | — | Yes |
| Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories) | — | Yes |
Wrist Fit
Garmin D2™ Mach 1 Pro
Sits best on wrists ~54–73mm wide (≈ 14.4–19.5cm circumference).
Garmin D2 Mach 2 51mm
Sits best on wrists ~54–73mm wide (≈ 14.4–19.5cm circumference).
Frequently Asked Questions
Is the Garmin D2™ Mach 1 Pro bigger than the Garmin D2 Mach 2 51mm?
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 D2™ Mach 1 Pro or the Garmin D2 Mach 2 51mm?
The Garmin D2™ Mach 1 Pro suits wrists around 54–73mm wide, and the Garmin D2 Mach 2 51mm around 54–73mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Garmin D2™ Mach 1 Pro and Garmin D2 Mach 2 51mm 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.