Workout

Warm-up (600)                   
2 rounds                        
100 swim/100 drill/100 kick                     

Set (600)
Swim 12 x 50's on :50 
...odd choice 
...even free (6 cb)

Set (2200)
2 rounds
10 x 100's on 1:25/1:20
...best average
...descend 1-2
100 kick on 2:00

Cool-down (200) 
Swim 200 
...moderate to EZ