Does anyone have any inside knowledge on whether anything has changed with the internal altimeter/temperature sensor in the 955 in terms of its use in swimming?
Every Garmin watch with an altimeter I've had has eventually had it fail, with varying arguments required with Garmin Support to get it replaced (depending on the age of the unit). I've managed to avoid it with my 5X by keeping it out of the pool entirely and using a sacrificial Fenix 3HR. But I'd really like to use the HR-whilst-swimming feature of the 955, and I note that with recent units Garmin appears to have discovered that the issue is the temperature sensor being powered on whilst in contact with chlorine, and has fixed it in some firmwares (sadly not the Fenix 5 series).
I also note that the altimeter hole seems to have moved to the back/bottom of the watch where it might in theory be better protected. I've seen comments elsewhere (eg DC Rainmaker's blog comments section) suggesting the issue might be direct exposure of the metal of the sensor to chlorinated water, and that some manufacturers avoid the issue by having it coated.
I dared to try my 955 in the pool last night and noted that temperature was selectable as a data field, and gave a reasonable number - though I removed it before going into the water (too scared!) and there doesn't seem to be a temperature recorded in Garmin Connect for the activity.
Grateful for any knowledge people might have, thanks!