Workout

Warm-up (500)
200 swim, 200 drill
100 kick

Set (500)
10 x 50's on :55
…odd: 25 fingertip/25 fr  
…even:25 R arm/25 L arm
           
Set (2000)  
2 rounds
4 X 50 build on :45
4 X 100 pace on 1:30 
2 X 200 on 2:45
...negative split

Set (300)
300 pull
...3 cb
 
Cool-down (100)
100 EZ free