which is better for swimming. Instinct 2 or 3

No big difference, if any at all. I3 might have slightly better buttons, perhaps. HR sensor is the same, thought the software might be better tuned up. I did not do any swims with my HRM-Pro and I3 yet, but I use them both for running, and was amazed by the accuracy of the wrist HR, which is almost always identical with the data from the strap.

Thank you.

I wonder if they fixed temperature sensor issue for swimming pools in 3 version

I wonder if they fixed temperature sensor issue for swimming pools in 3 version

The heart rate sensor is not the same! The Instinct 2x has a flat, glass sensor. The 3x version has a plastic, convex sensor like the instinct 2 version.
If that's not the case, please correct me.

mi.strnadel said:

If that's not the case, please correct me.

Instinct 2X has the same sensor as the standard edition of Instinct 2, it just has a ring frame around it (perhaps with a glass over the sensor, but I cannot confirm it, since I do not have it). And all versions of Instinct 3 have the same sensor too (without the frame, and without glass). It is the Elevate 4 generation.

From left to right - Instinct 2, Instinct 2X, and Instinct 3:

Elevate 5 looks like this (on Fenix 8):

And Elevate 3 on the old Instinct (1st gen) is also different:

The Instinct 2x has a glass straight sensor. Instinct 3 has a plastic sensor, rounded.

Yes, the sensor cover is different, but the underlying sensor itself, in both watches, is the exact same Elevate 4 sensor.

HTH

So true. I’m very disappointed with the lack of support for Instinct 2X. Even forum mods tried to convince us the support is ongoing. Yet no new beta for more than six months clearly show the “support” we are getting.