21 minutes with rate increase
Row a single 21 minute piece. Row the first six minutes @ 20 spm. Then row five minutes @ 22 spm, four @ 24, three @ 26, two @ 28 and one @ 30.
10,000m with rate changes every 2000m: 22-24-26-24-22
Row for a total of 10,000 meters at a sustainable intensity, varying your stroke rate as follows: row 2000 meters @ 22 spm, 2000 meters @ 24 spm, 2000 meters @ 26 spm, 2000 meters @ 24 spm, and 2000 meters @ 22 spm.
Marathon time trial
Row a 42,195 meter time trial, going for your personal best. After you've rowed, enter your time in the Online Ranking and see where you stand with others of your age, gender and weight class.