Had a new one today with a wet runway. The B737 ahead of us started its takeoff roll as we took the turn to the holding area. We never stopped more than a few secs before turning onto the active runway in a rolling takeoff. As we were just finishing the turn while accelerating I looked down the runway and the B737 was still throwing up rain water probably between V1 and lift off. I judged if the first plane was to abort and remain on the ground we would overfly it. This concerned me somewhat even thou it turned out to be nothing. I suspect that the judgement was either by the ATC clearance or a misunderstanding by our crew.