Swim zones : from Z1 recovery to Z5 VO2max
SwimFive pace levels anchored on CSS, simpler than bike zones.
Swimmers typically use Z1 (recovery, > CSS+10 s/100 m), Z2 (endurance, CSS+5 to +10), Z3 (tempo, CSS+2 to +5), Z4 (threshold, CSS-2 to CSS+2), Z5 (VO2max, < CSS-3). Everything anchors on CSS : no lactate testing needed.
In TriPaced:
In TriPaced, every prescribed swim interval shows an absolute pace target (s/100 m), not a zone tag: you read "1:35 / 100" directly : the app already converted from your CSS.
Source Sweetenham B. & Atkinson J., Championship Swim Training (Human Kinetics 2003) - zones anchored on CSS/T30 protocol