My brother finished the first version of his Phantom floats this morning and tried them out in the pool and in flight. The entire contraption comes in at 233 extra grams. It does bring the horizontal speed down to about 22mph, the tips of the bottles come into view at some points during flight, and we think that there is some distinct prop wash when coming straight down to land, as it does come down a little kooky... but there could also be some blockage of the vision positioning system. He's going to try bringing the floats out some more to minimize the prop wash, and keep them out of camera view, try to block the VPS less, and has lighter bottles to use also. But it is very stable in the water, and we both think that this first attempt was a success. Yes it was slower, but he's willing to accept the slower speeds, if he can gain the ability to take off and land in the water if he wants to. They are easily removable and there is no permanent damage to the aircraft. He will keep working on them and I'll keep you updated.