Workout

Warm-up (600)
300 swim, 200 kick, 100 drill

Set (600)
2 rounds
100 kick, 100 swim, 100 kick on 5:45
...emphasize the kick

Set (1600)
2 rounds
Swim 2 x 300 free on 4:15
...descend 1-2  
Swim 200 on 3;00 
...50 back/50 free
....focus underwater distance  
...round 2 faster than round 1

Set (600)
Pull 2 x 300 free on 4:15
...5 cb  

Cool-down (200)
Swim 200 moderate to EZ