This is a test designed to give correlation with the 2k test simply by doubling the result. It is rate capped for a reason. Do not rate cap over 24! Work as hard as you can every stroke with maximum power. Keep to the rate and if you find you are over the top approaching the end drop the rate down till the average hits the target by the end. Even it is only half a pip over 24 it will not count for the test. It is also good all round training for strength component.
The segment length (split time capture) should be set at 250 m on a C2. That means you need to set your machine at that setting before you do the piece.
Always check the programme set before you set your machine parameters so they coincide.