Check out some of the main threads on the race. I saw some posts that said other races that use the same channel of water around that time of the year usually see water temps in the 74-77 range. It will be on the edge. The currents are also a moving target. Some years there was no benefit. Other years people felt a small current. Someone predicted 1-5 minute gain for a 1:15 swimmer over the IM distance.