E-Flite Timber on the river; early morning,July 4th

Got out to the Penobscot River around 9:30 am on July 4th; just a half hour before low tide, to fly the Timber off the river. The best time (tide wise) would have been around 10:30-11am as the tide started coming back in slowing the rivers current down and providing quieter water, But the forcast was for 97 degrees today and it was heating up quick.
Been battling this tick with the plane on floats as of late. It all the sudden started about a year ago, when after several good takeoffs and landings, the Timber started to turn left when accelerating on the water, followed by a sudden Right turn when trying to gently correct for it.. If not handled correctly it would result in a right hand ground loop on the water. Tried several things, but still haven't been able to remedy that issue. You can tell that I was working on that today as well.