TetherSwim is built for swimmers training with resistance cords, swim tethers, or endless pools. Traditional swim trackers can struggle with these sessions, giving you wildly inaccurate distances or ignoring your efforts altogether.

With TetherSwim, your distance is estimated intelligently based on your real stroke count, SWOLF, and previous swim history — all from your Apple Watch.

Features:
• Accurate distance estimates – Uses your stroke rate, efficiency, and past workouts to calculate real swim distance.
• Automatic SWOLF tracking – Measures your swim efficiency in tethered conditions.
• Calories, heart rate, and more – Full workout data, just like in regular pool swims.
• Exclude test swims – Keep your baselines clean by excluding warm-ups or experiments.
• Strava integration – Upload your tethered swim sessions directly.
• Water Lock mode – Automatically engages when you start, so your watch screen won’t go crazy mid-session.