Now that you know you could finish in an avg pace of 2:01.9, get right on that for the first 3k, then use the "rule of halves" - At each halfway point, either speed up the pace being displayed by 1 second or continue with the current pace depending on how you are feeling. i.e. points to pick up the pace on a 6k are 3k, 1500m, 750m, 375m, ~200m, ~100m to empty.
You should be feeling pretty good at the halfway point, but if you are still feeling good by the 3/4 point you could have started faster. Just don't bite off more than you can chew. 1 second in Avg pace is 12 seconds off over the full 6k, and you will get to a point where that is too big a bite eventually.
Plus, if you are totally flailing at the end, that wouldn't be very useful in a boat anyhow, so maintain form along the way.
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