No not manually ….
If you have an Apple Watch 2 /3 or and you use Strava you’ll be as frustrated as I am that Strava doesn’t support swimming on the watch. You have to record any swim that you do using the watch’s native Workout app (which works really well), then manually create a new activity in Strava and fill in the details. There is quite a thread developing on the Strava Support forum requesting swim support for Apple Watch 2 / 3 and I would urge you to add your name to it. However, I have just discovered the Swim Exporter app that connects with Apple Health and Workout data and imports the information into Strava when you record either a pool swim or an openwater swim using the Workout app. It costs £1.99 and is incredibly simple to use: simply connect it to your Health app and link it to Strava and it will automatically display all swim workouts. To upload a workout to Strava, just click on the workout and click, “Send to Strava”. Job done.
Shame Strava don’t do a swim part for their watch app