Warm up:
200 Swim, 100 kick, 100 drill of choice. See this post for a few examples.
10 x 50 on 1:00 or 1:15 breath every 3 (this is a breathing drill exercise don't worry about speed)
Main set:
500 swim build
50 easy
400 swim build
50 easy
300 swim build
50 easy
200 swim build
100 easy cool down
Total: 2550 yards (this includes all warm up and easy swims)