Tracking heart rate during swimming helps manage effort, monitor training load, and tailor workouts for performance and recovery. Water creates unique measurement challenges, so the best monitors for swimming combine waterproof design with sensor placement that stays in place as you swim. This guide highlights five top options from Garmin and Polar: Garmin Swim 2, Polar OH1, Polar Verity Sense, Polar H10, and Garmin HRM‑Dual. Each offers a different style—watch, armband, or chest strap—so you can choose the option that best fits your stroke, pool or open-water routine, and device ecosystem.
| Product | Type | Connectivity | Water Resistance | Best For |
|---|---|---|---|---|
| Garmin Swim 2 | GPS Swimming Smartwatch | Bluetooth, ANT+ | Waterproof (pool/open water) | Pool and open-water swims with tracking |
| Polar OH1 | Optical Heart Rate Monitor | Bluetooth, ANT+ | Waterproof | Arm-based, goggles-friendly swimming |
| Polar Verity Sense | Optical Heart Rate Monitor Armband | 2 Bluetooth channels, ANT+ | Not specified | Versatile sport use, includes swimming |
| Polar H10 | Chest Strap | Bluetooth, ANT+ | Waterproof | High-precision HR across devices |
| Garmin HRM‑Dual | Chest Strap | Bluetooth, ANT+ | Not specified | Reliable HR for Garmin devices |
Garmin Swim 2: Underwater HR & GPS Swim Watch
The Garmin Swim 2 is a dedicated swimming smartwatch designed for pool and open-water workouts. It provides GPS tracking for distance, pace, stroke count, stroke type, and SWOLF, helping swimmers assess efficiency. The device supports underwater heart rate monitoring, enabling HR insights while you’re in the water. Battery life is robust: up to seven days in smartwatch mode, 13 hours with GPS and optical HR, and up to 72 hours in pool mode with HR tracking. This makes it suitable for both daily training and longer sessions without frequent recharging.
- Underwater heart rate monitoring and swimming-specific metrics
- SWOLF, stroke type, and distance tracking
- Pool and open-water compatibility with long battery life
The Swim 2 integrates with Garmin ecosystem tools, allowing you to review workouts, set training plans, and export data for in-depth analysis. While primarily a watch, its built-in GPS and HR capabilities provide a comprehensive picture of aquatic performance without needing a separate strap.
Polar OH1: Waterproof Optical HR Monitor For Swimming
The Polar OH1 is an optical heart rate monitor designed for freedom of movement in water. It can be worn on the arm or temple, with a soft textile armband for comfort and a goggle-strap clip to secure it during swims. Its waterproof design makes it suitable for pool workouts, and its connectivity options include Bluetooth and ANT+ simultaneously, enabling pairing with Polar Flow, third-party apps, or smartwatches. The OH1’s versatility makes it a strong choice for swimmers who want accuracy without a bulky chest strap or wrist device.
- Arm or temple placement with goggle strap clip
- Soft armband for secure, comfortable wear
- Bluetooth and ANT+ simultaneous connectivity
Because it is optical rather than chest-based, OH1 may experience slight optical reading variations during intense swimming, but its water resistance and flexible mounting make it a popular choice for swimmers who value comfort and minimal drag.
POLAR Verity Sense: Armband Optical HR Monitor
Verity Sense is a versatile optical HR monitor worn on the arm, with options to clip it to goggles or wear it under clothing for stable readings during swimming. It emphasizes comfort and freedom of movement, with a slim 3 cm width. The device offers 2 Bluetooth channels and limitless ANT+ connections and supports live heart-rate broadcasting, making it easy to stream HR data to multiple apps and devices in real time. A 30-hour battery life provides endurance for longer sessions and multiple workouts between charges.
- Arm/clip-on design for stable wear during swims
- 30-hour battery life and flexible connectivity
- Live HR broadcasting and many ANT+ connections
The Verity Sense is suited for swimmers who want a lightweight, sleeve-friendly sensor that doesn’t require a chest strap, while still delivering robust data across platforms and apps.
Polar H10 Chest Strap: Accurate Waterproof HR Monitor
The Polar H10 chest strap is widely recognized for high accuracy in heart-rate measurement. It uses Bluetooth, ANT+ and 5 kHz for broad compatibility and can support multiple connections simultaneously. This makes it a strong choice for swimmers who want precise HR data to drive workouts across a range of devices and apps such as fitness watches, gym equipment, and cycling computers. The H10’s waterproof construction supports swimming sessions without compromising data integrity, and its strap remains secure during vigorous movements.
- High-precision HR readings
- Bluetooth, ANT+ and 5 kHz compatibility
- Supports concurrent connections across devices
For swimmers who train with multiple devices or gym systems, the H10 offers reliable, cross-platform data while maintaining comfort and durability in water.
Garmin HRM‑Dual: Flexible Chest Strap
The Garmin HRM‑Dual chest strap offers a comfortable, adjustable fit and reliable data transmission via Bluetooth and ANT+. The module is removable for washing, and the battery life is designed to require infrequent replacements. This makes it a practical choice for swimmers who value a durable, adaptable strap that can pair with Garmin devices and other compatible equipment. While the data in the listing focuses on comfort and durability, this model is a solid option for those who want a dedicated HR monitor without relying on wrist-based sensors in a stroke-heavy session.
- Soft, adjustable strap for comfort
- Removable module for easy washing
- Long-lasting battery and reliable cross-brand compatibility
With its reliable dual-band connectivity, the HRM‑Dual is well-suited for swimmers who train with multiple gadgets or who want precise HR data during workouts and post-swim reviews.
Buying Guide
Sensor Type and Accuracy
Choose between chest-strap sensors and optical (armband) sensors. Chest straps, especially when paired with ANT+ or Bluetooth, typically provide highly accurate HR readings and HRV data, which is valuable for intensity control and training load. Optical sensors on the arm offer comfort and less drag but can experience small variations during heavy swimming or unusual arm motions. For open-water swimming, a device that supports reliable underwater readings or robust external connectivity often proves most practical.
Water Resistance and Durability
Ensure the monitor is explicitly designed for swimming. Models described as waterproof or designed for swimming (such as Polar OH1, Polar H10, and Garmin Swim 2) are better suited to routine pool sessions. Read the manufacturer’s guidance on depth, pressure, and recycling of components after exposure to chlorinated water or saltwater. A secure fit—whether armband, goggles clip, or chest strap—helps maintain consistent readings in water.
Connectivity and Ecosystem
Consider how your HR data will sync with devices and apps. Some monitors offer Bluetooth, ANT+, or 5 kHz, and can stream data to Garmin Connect, Polar Flow, third-party apps, or smartwatches simultaneously. If you already own a device ecosystem, prioritize compatibility to streamline data analysis, workout programming, and progress tracking.
Battery Life and Charging
Battery longevity matters for longer sessions or multi-day training camps. Some devices provide extended life in specific modes (for example, Garmin Swim 2 offers several days in smartwatch mode but shorter spans when GPS and HR are active). Armband monitors and chest straps vary in battery life; Verity Sense delivers up to about 30 hours of battery life, while others may offer longer durations depending on usage. Always factor charging time into your plan.
Comfort, Fit, and Swim-Specific Metrics
Comfort is key in water workouts. A snug, secure fit reduces movement-related noise in readings. Look for straps or armbands designed for swimmers and metrics that support swimming analysis, such as stroke type, SWOLF, distance, pace, and HRV, so you can translate data into actionable training decisions.
Value and Use Case
Assess whether you want a dedicated swimming watch, a chest strap for accuracy, or a flexible optical option for swimming and other sports. If you train across multiple activities, a device with broad compatibility and easy data export will save time and provide a more complete picture of your fitness over time.