Most Polar products can be worn when swimming. They are not, however, diving instruments. To maintain water resistance, do not press the buttons of the product under water. When measuring heart rate in water, you may experience interference for the following reasons:
- Pool water with high chlorine content, and seawater are very conductive. The electrodes of the transmitter may short-circuit, preventing ECG signals from being detected by the transmitter.
- Jumping into water or strenuous muscle movement during competitive swimming may shift the transmitter to a location on the body where ECG signals cannot be picked up.
- The ECG signal strength is individual and may vary depending on the individual’s tissue composition. Problems occur more frequently when measuring heart rate in water.
Those Polar products that use only 2.4 GHz (W.I.N.D. or BLE) transmission will not measure heart rate under water. See also related documents. If you're swimming in salt water or highly chlorinated water, or have repeated challenges measuring heart rate in swimming, we recommend that you use the T31c heart rate sensor.
In the watch industry water resistance is generally indicated as meters of water pressure, which means static pressure of water at the level in question. Polar uses this same indication system. Water resistance of Polar products is tested according to International Standard ISO 2281. Every Polar device that has water resistance indication is tested before the delivery to stand water pressure.
Polar products are divided into four different categories according to their water resistance. Check the back of your Polar product for the water resistance category, and compare it to the chart below. Please note that these definitions do not necessarily apply to products of other manufacturers.
When performing any underwater activity, the dynamic pressure generated by moving in water is greater than the static pressure. This means that moving the product under water subjects it to a greater pressure than if the product were stationary.
|Marking on the back of the product||Wash splashes,
sweat, raindrops etc.
|Bathing and swimming||Skin diving with snorkel
(no air tanks)
(with air tanks)
|Water resistant characteristics|
|Water resistant||OK||-||-||-||Splashes, raindrops etc.|
|Water resistant 30/50 meters||OK||OK||-||-||Minimum for bathing and swimming*.|
|Water resistant 100 meters||OK||OK||OK||-||For frequent use in water but not SCUBA diving.|
|Water resistant IPX7**||OK||-||-||-||Do not wash with a pressure water|
*) These characteristics also apply to all Polar WearLink transmitters.
**) International IEC 60529 IPx7 Standard.