@mvpereira I used a Polar OH1+ (which is fundamentally the same as the Verity) by wearing it on the same wrist as the Ambit3 and found that the signal travelled 2-3cm under water and thus the connection remained if I wore them close enough together.

I’m now using a Fenix 3 on which Garmin have disabled recording of HR when swimming and I use the OH1 in recording mode, export the file from Polar Flow after the swim and then add it to my swim workout in TrainingPeaks - TrainingPeaks then combines the HR and the swim details from the Fenix 3.

Either option should work for the Ambit3.