The Army Corp of Engineers web sit has some graphs of water temps for the Ohio River. There was nothing available for Upper McAlpine, which is closest to where we swim but I found some graphs further up river and the water temps were close to 80 plus or minus a few degrees. In the days before the race, it is suppose to be wet and cooler up stream so I would guess the temps would be on the low end of the recent range (78 degrees F?).

Now the question, if it ends up 78 degrees, do you risk overheating in a wetsuit?

I don't know...Don't think I've ever tried 78 in a wetsuit. Sounds toasty. What do you think?

My wife is a tri swim coach and she said - for someone as challenged as me (closer to 1:30) - YES! plus my wetsuit is sleeveless. But if you are closer to 1:00, maybe not.

I have a two piece wetsuit (DeSoto). I know I'll wear the bottoms for sure. My problem is deciding whether to just go shirtless or wear the sleeveless top for the wetsuit? It seems like I'll get most of the benefits from the bottoms without the concern of overheating.

http://www.weather.gov/...rodtype=hydro#RVALMK,
Markland about 50 miles upstream is showing 81 degrees.
Cannelton which is downstream is showing 76 its about 50 miles(not river but driving) the other way.
Don't know how accurate they are though. the one in louisville mcalphine hasn't had a temp reading for quite a while.

I'd pack it anyway just in case.