For time:
Row, 500 m
50 Double Unders
50 AbMat Sit-ups
Row, 400 m
40 Double Unders
40 AbMat Sit-ups
Row, 300 m
30 Double Unders
30 AbMat Sit-ups
Row, 200 m
20 Double Unders
20 AbMat Sit-ups
Row, 100 m
10 Double Unders
10 AbMat Sit-ups
Sub Double Unders with 2x Single Unders. Target time is around 15 minutes.