Workout

Warmup (500) 
300 swim/100 drill
100 kick

Set (600)     
6 rounds        
50 scull on 1:15
50 kick on 1:05
        
Set (1600)      
100 on 1:30
200 on 3:00
300 on 4:30
400 on 6:00
300 on 4:15
200 on 2:45
100 FAST
        
Set (600)
12 x 50 swim
...D 1-4 

Cool-down (200)
200 EZ choice