I wore my Garmin 620 in an indoor pool yesterday for a lap swim, and it incorrectly measured the distance (as I'd expect). Each of the laps were 100 yards (91.44 meters) for a total of 1,500 yards (1,371.6 meters). I tried to edit the TCX file manually to show this, but doing so messed up the split times no matter what I did. I changed each <DistanceMeters> tag to 91.44, but of course that doesn't fix the total distance, and even doing just that made it show incorrect split times when I uploaded to Strava. (I wasn't touching times at all, so I'm not sure how that happened.) Then I tried doing that, as well as modifying the <TrackPoint> tags to more appropriate distances, but that didn't seem to work either. Is there a way to fix this that I'm missing?
