First time I use the swim workout, I just love the way it syncs with Garmin and makes the swim workout easy to follow.
That being said I have noticed discrepancies around the swim zones.
My critical pace is set to 1:37/100y, zone 4 is 1:35 to 1:27
Now in today’s workout in the calendar it says L4 is 1:20 to 1:27/100y (so faster than zone 4 ?)
And on my Garmin, I saw displayed 1:13 to 1:20/100y (I don’t have a screenshot on this one), I just can wish I could swim that fast 
Also I have noticed my critical pace falls into zone 3b while my wife’s one falls into zone 5
