Active watch heart rate too high during swimming

[gx221]

When I swim with Active watch, my heart rate measures usually goes up to 155.  That is higher than actual.   Other days it measures no more than 130.  My effort is the same, same strokes, pool temperature  is similar.   I swim 80 laps.  

The watch band is quite snug.  I found that one time I tighten the band even more and the rate goes down to what I expected.

Has anyone seen heart rate affected by band tightness? 

[WojciechCzyz]

I am having Galaxy Watch 3 and 219 PPM peaks were recorded yesterday... I believe recording is wrong

[Aaron Madrigal]

I had a similar issue with my Galaxy Watch, after a  muddy gardening day it started to record very low (ca. 35 ppm) while sleeping.

I normally wore the strap quite tight.

I tried with another smartwatch, and measure was consistent with previous data.

I guess they need to improve on the water resistance or the sensor.

[Borris1]

I notice the same. When the strap is tight I average 140 with a peak of 152. When the stap is not tight like today I average 171 and a peak of 207. Can't be right. At 62years 207 would kill me.

[Members_LTisiqT]

Yep Bro,

I found the same issue, my measured HB while swimming looks higher then actual, yesterday it recorded a (wrong of course) peak of 191...