I *did* try to look at the relationship between discharge and finish times, but we only have two years of data for the 36-mile race.

The attached is a plot of finish times (hours) as a function of discharge (cubic feet per second). I added a basic linear regression line, which goes through the mean finish times. Not only do people get slower as discharge drops, but the range of finish times increases. I haven't had time to predict any sort of range for the flows we're seeing now, but you can eyeball it and see that we may be in for an interesting year.

Using the first two years of finish times might be informative if I translate the data into average mph rather than finish time, but I have an inkling that the 27-mile swimmers were going a little faster on average than 26-milers--but I could be wrong about that.

I find it interesting how close some of the times are. Having paddled, I know that people often jockey back and forth for position along the course, but I wonder what sort of times we would see if these were all solo efforts.