The float pond you mentioned was at the Roseburg, Oregon Airport and we had a float pond and flew CL float planes off the 1/2 circle of water at the NW Regionals. Here are just a few of the models that were flown off the circle.
This was used for almost 4 years and what an incredible experience. I flew a 7' span piper cub, 41" span Grumman Tigercat on floats, and even my camera plane all with electronic controls for throttle control. We had lots of models, even stunt models were flown with floats.
The red white and blue model with no rudder has a 7' wingspan and a four stroke .91 for power
Here are some pictures from the 2001 contest.....!
Fred Cronnewett
CL scale and float flying