Yes, Pool Swim is available, just tested on Series 4 running watchOS 7.
Start a swimming workout
- Open the Workout app on your Apple Watch.
- Choose Open Water Swim or Pool Swim.
To pause or resume your swim, press the Digital Crown and side button at the same time.
When you start a swimming workout, your Apple Watch automatically locks the screen with Water Lock to avoid accidental taps. When you’re out of the water to rest or because you’ve finished your workout, turn the Digital Crown to unlock the screen and clear any water from the speaker. You hear sounds and may feel some water on your wrist.
The Apple Watch Series 1 and Apple Watch (1st generation) aren’t suitable for swimming. See Important handling information for Apple Watch.