That link was for the water temperature on Nov 24 at Sarasota Beach, not the race site. HITS Sarasota is in a shallow lake (Nathan Benderson Park) built for rowing competitions and the actual water temperature will be determined by the air temperatures experienced during the week preceding the event. For example, Gulf temperatures at Clearwater Beach were around 70 a week ago. We had a strong Florida "cold snap" this week that pulled the Gulf down to 62 by Wed. It went up to 63 on Thu and 64 this morning. I'm racing OWS tomorrow and anticipate 65.
Sarasota HITS water temperature will fluctuate even more than the Gulf depending on the weather. I don't believe there is any organization or person that takes regular water temperature readings in that lake. But for that time of year, mid 60s is a good GUESS.