In Daisy configuration the turbines dive during the rotation, involving a control of ballasts tanks, otherwise the density of the hydro-turbines-ring should be the same as the water density.
In Rotating Reel configuration all the ring is floating, with also a possibility for the ring (not the hydro turbines) to rise above water with foils in order to save a part of the hydro drag. In the other hand the ring can dive a little due to the kite force, but at least it is not necessary to vary its density as it is always floating, and the risk of damage is lesser.