Found this on a blog I follow: NTC Masters Workout - the coach does an awesome job of throwing up routines to use. This one is a good one I think I'm going to strive to achieve as I embark to lose my stomach.

450 warm up (100 swim/50 kick)

6x25 kick @ :60 (1 easy/1 FAST!)

3 x [100 easy swim w/:15 rest

50 FAST!! kick w/:30 rest]

50 easy

6x25 pull @ :60 (long strokes)

3x150 pull w/:30 sec rest

6x25 @ :60 drill

6x75 w/:30 sec rest (free/non free/free by 25)

100 cool down

*2500 Total*