Workout

Warm-up (600)
300 swim
4 x 50 on :55
...25 free/25 drill
...underwater recovery

Set (600)
12 x 50 on :55
...25 kick/25 swim

Set - T30
...30 minute swim
...record distance

Set (10 mins)
Vertical kick
6 x :30 
4 x 1:00
2 x 1:30

Cool-down (200)
200 easy swim