Tips to Improve Accuracy of Pool Swim Activities

Garmin® watches that support pool swim activities use arm movements and preconfigured data, such as pool size, to provide swim metrics when recording a pool swim activity. Swim distance is computed by detecting your turns in the pool. Individual differences in swimming style and training styles may cause errors in the reported distance. The information provided in this FAQ describes the main reasons for distance inaccuracies and ways to potentially improve accuracy. 

What Can Cause Swim Distance to Be Incorrect?

Discrepancies in the distance of your recorded Pool Swim activity can be caused by multiple sources.

Over Reporting Distance

If the watch is over reporting distance, it is typically because of how you are swimming or turning at the end of the length. The watch looks for a pause in strokes to indicate you have reached the end of a length. A slow swim pace or stopping mid-length could cause the watch to register an additional length. If auto rest is enabled, a lot of arm motion while resting can also cause over-reporting.

Under Reporting Distance

If the watch is under reporting distance, it is because the device is not properly detecting your turns. Ensure you do a strong push-off followed by a long streamlining (glide) phase before you start swimming.

NOTE: The type of turn (flip, touch, open) does not matter as long as you have a long glide following the push-off.

Other Factors to Consider

• Disruptions mid-length, such as:

  • Changes to speed or stroke cadence mid-length (including stopping or walking).

  • Interruptions from other swimmers.

  • Switching stroke type mid-length.

• Inexperience in lap swimming.

• Performing drills that affect arm motion.

  • Using the Swim Drill Feature on Garmin Fitness Watches.

• Slow swim pace. Our swim algorithm is tuned for swimmers that swim a 25 meter length in less than 45 seconds. Slower than this may result in no distance being recorded.

• Using a stroke type that is not one of the four recognized competitive stroke types (freestyle, breaststroke, backstroke, and butterfly stroke).

NOTE: When stopping to rest at the end of a length, the distance displayed on the watch may lag behind one pool length for a few seconds but should correct itself when you press Lap to start your rest or when auto rest kicks in (if enabled in settings). 

How Can I Improve the Accuracy of the Swim Distance Recorded on My Watch?

To maximize accuracy, ensure the following:

• Set the correct pool size prior to starting the timer.

• Swim continuously throughout the length, using one stroke type at a consistent pace and stroke cadence.

• Use a strong push-off from the wall and a long streamlining (glide) phase.

• Use drill log for drills that affect arm movement. If a drill log is not available, ensure auto rest is turned off and then use rest intervals for drills that affect arm movement.

• Use one of the four recognized competitive stroke types (freestyle, breaststroke, backstroke, and butterfly stroke).

• If resting between lengths, use rest intervals or ensure auto rest is enabled in settings.

  • If auto rest is enabled, minimize arm movement during rests or turn off auto rest and use the Lap button to mark rest intervals.

As your swimming technique advances with practice and the use of the tips above, distance accuracy on your watch will improve. Experienced swimmers can also try wearing the watch on the other wrist if they are still encountering errors.