Workout

Warm-up (500)
400 Swim
100 Kick

Set (400)
8 X 50 on 1:00/:50
...odd kick, even swim  

Set (1500)
4 X 100 on 1:30
...descend 5 sec per 100
200 fast
50 easy

3 X 100 take off lowest interval
150 fast
50  easy

2 X 100 take off lowest interval
100 fast
50  easy

1 X 100 at the fastest interval
50 fast
50 easy

Set (200)
8 x 25 odd sprint, even easy

Cool-down (400)
200 moderate
200 EZ