Swim Pool HR wrist vs HRM TRI belt on fénix 6

Activities set to private, you have to make them public for us to see them.

For my ~1 hour swimming activity (tested with beta fw 5.77) breaststroke WHR was total crap - some 15-25 bpm higher on average vs. chest strap data, but for backstroke it was very good with only 2-5 bpm difference.

My experience too. THe pattern of the response from the OHR matched how I felt it should with the rests and efforts but I always believed (based on RPE) that it was high. Got a HRM-Tri recently and it was as you’ve found. It’s still a work in progress. 

However, a friend of mine has great correlation between the two so it works for him.

on the HRM-TRI is lover BMP than hr from watch 

Yes HR from fenix 6 wrist sensor is much higher (+25bpm for me) ... but not take it as a statistic as I try this setup only once. However I have HRM TRI for several years and I know that the HRM TRI HR data are very consistent (both in water and out of water).

WHR when swimming typically works OK for me (I did make some posts on this for OWS back in September/October).  An example from pool swimming comparing Fenix 6XPS WHR to HRM Tri during my pool swim last Thursday is below.

https://connect.garmin.com/modern/activity/4463649119

[Warning - geek alert!!! I found a little trick that the 6X PS records both the WHR and the HRM Tri 'store and forward' data to the fit file.  Connect knows to display the HRM Tri data in preference to WHR, but data comparison tools typically show the WHR from the fit file, whereas the tcx file exported from Connect only has the HRM Tri HR data.  So that makes a direct comparison of WHR to HRM Tri possible, as shown in the chart above.]

How do you get the watch to use the WHR sensor when an HRM Tri is being used?

I'm new to chest straps so I don't know a lot about them yet, but when I use my HRM Dual it automatically turns off the WHR sensor (the green light is off) as soon as the watch sees the chest strap. I wasn't able to find a setting anywhere that would force WHR to stay on.

C.sco said:

but when I use my HRM Dual it automatically turns off the WHR sensor

If you are using HRM Dual then I can only assume you're not using it swimming (HRM Dual is not a swimming compatible strap with 'store and forward'). It only works whilst swimming when connected to HRM Swim or HRM Tri, where it would be expected that the strap won't talk to the watch 'live' during the swim, but send the stored HR data to the watch afterwards.  This means that whilst swimming you'll see the live WHR data on the watch (as the watch can't talk to the strap through the water) and in Connect afterwards you'll get the strap data, which gets sent to the watch when you save the activity after getting out of the water.

If you want to compare WHR to strap for the same activity for non swimming activities, then turn off the strap in the Sensors and Accessories settings and install/add this CIQ data field https://apps.garmin.com/en-US/apps/a461bc0d-828d-47c8-a4a5-8d014b5fedc9.  Afterwards in the interweb version of Connect, you'll be able to compare the WHR data in the HR field to the CIQ Auxiliary Heart Rate data.

Makes sense, thank you!