Ideas.
Warm Up - 200 m easy swim
Main - 6 x 75 m water polo or drill @ :10 rest (mix up your lengths - trudge, stop & go, roll over, zig zag, scissor starts, sliding, spider, blocking, swim to set, water polo backstroke, CU, HU, swim & jump, swim & block, change directions)
Pick one of the following:
4 rounds [200 swim @ :15-:20 rest + 200 legs only] 2 minutes between sets (early in the season - you can add variety by doing some swim & some water polo
4 rounds [4 x 100 swim @ :05-:10 at a good pace] 2 minutes between sets
4 rounds [1st round 5 x 100 swim + 0 x 50; 2nd round 3 x 100 swim + 4 x 50 fast; 3rd round 1x100 swim + 8 x 50 fast; 4th round 10 x 50 fast]
4 rounds [5-8 x 50 @ pace (:05 rest)] 2 minutes between sets
Drop set - this set requires you to know your pace and be good at calculating times
Start the set @2:00 and drop :05 each repetition (the final repetition should be on :20 to :25). Swim 100-150 (depending on your pace) for the 2:00 pace time, drop your distance by one length each time you fail the pace time.
Ex: swim 100 @2:00, 1:55, 1:50, 1:45, 1:40, 1:35 but cannot make 100 on 1:30 so on that repetition you would only swim 75 (
swim 75 @1:30, 1:25, 1:20
swim 50 @1:15, 1:10, 1:05, 1:00, :55, :50, :45
swim 25 @:40, :35, :30, :25, :20
4 rounds [12-16 x 25 @:30-:35] play with the starts, HU, with or without a ball 2 minutes between sets
Cool down - easy backstroke