Garmin Forerunner 265 vs Polar Vantage V3: Which GPS Watch Wins?

Overview

The Garmin Forerunner 265 is a mid-range running watch for serious recreational runners who want accurate GPS, training load metrics, and a sharp AMOLED display at $449. The Polar Vantage V3 is a $599 flagship built for endurance athletes who prioritize deep recovery analytics, longer battery life, and a purpose-built training tool over smartwatch features. These two watches share a price neighborhood but target different levels of commitment.

Specs at a glance

Price: Forerunner 265 ~$449 vs Vantage V3 ~$599
GPS battery: 265 gets 13h multi-band / 20h standard GPS; Vantage V3 gets 43h multi-band GPS
Smartwatch battery: 265 rated ~13 days; Vantage V3 ~7 days
Display: Both 265 and Vantage V3 use AMOLED touchscreens (1.3in vs 1.39in)
Weight: 265 at 47g vs Vantage V3 at 55g
Water resistance: 265 rated 5 ATM (50m); Vantage V3 rated 10 ATM (100m)
Heart rate sensor: Both use wrist optical PPG; neither is an ECG chest strap
GPS constellation: Both support multi-band multi-constellation (GPS, GLONASS, Galileo)

GPS and tracking accuracy

Both watches use multi-band GNSS and perform well in challenging conditions. The Forerunner 265 handles urban canyons and tree canopy without significant drift, though Garmin's post-processing applies aggressive smoothing that can mask raw variability. The Vantage V3 in back-to-back testing against a Garmin Fenix 7 Pro showed distance deltas under 0.05 miles over 10-mile efforts, and pace data during interval work lags under two seconds. That responsiveness matters for structured workouts. On raw GPS fidelity, the two watches are close. The Vantage V3 has a slight edge in pace responsiveness during intervals; the 265 benefits from Garmin's mature map-matching algorithms for post-run review.

Battery life

This is where the gap is stark. The Forerunner 265 delivers 13 hours in multi-band GPS mode. That covers most marathon efforts and sprint triathlons, but it falls short for long-course triathlon or ultramarathon use. Drop to standard GPS and you get 20 hours, which extends the range, but multi-band accuracy is the reason most people buy this watch. The Vantage V3 offers 43 hours in multi-band GPS mode with optical HR active. That covers a full Ironman with room to spare, or a 100-mile trail race. The Vantage V3 wins this category without contest for any athlete doing events over six hours.

For athletes: who wins?

Road running (5K to marathon): Forerunner 265. Lighter, excellent GPS accuracy, strong training load metrics, and 13 hours of multi-band GPS is more than enough. The AMOLED screen is easier to read mid-run.
Trail and ultrarunning: Vantage V3. The 43-hour multi-band GPS battery is the deciding factor. No one wants to manage power modes during a 24-hour mountain race.
Triathlon (Olympic and sprint): Forerunner 265. Battery covers the distance, Garmin's multisport mode is mature, and the 5 ATM water rating handles open-water swims. Saves $150.
Long-course triathlon and Ironman: Vantage V3. The 43-hour GPS runtime is essential. The 10 ATM water resistance adds confidence. Recovery analytics from Polar are among the best available from wrist-based PPG sensors for steady-state efforts.
Recovery monitoring: Vantage V3. Polar's recovery ecosystem is deeper, with continuous nightly SpO2 logging and HRV-based readiness tools that have been refined over years. The 265's HRV data has been flagged in academic review as unsuitable for serious athlete monitoring.

Verdict

Buy the Forerunner 265 if you run road races up to marathon distance, do sprint or Olympic triathlon, and want a lighter watch with a longer smartwatch battery and a proven Garmin ecosystem at $150 less. Buy the Polar Vantage V3 if you do long-course triathlon, ultras, or any event that pushes past 13 hours, or if recovery analytics are central to your training. The Vantage V3's 43-hour multi-band GPS battery and deeper recovery toolset justify the premium for serious endurance athletes. For most recreational runners, the 265 is the smarter buy.