I have tried lots of different floats on multirotors. In my experience, anything which has enough volume to float the bird will get pushed around by the slightest wind and will likely show up in the camera view. Even if you are lucky enough to fall buttered side up, there is still risk of flipping over. These birds are top heavy and wind, current or waves can tip them over. Those wood dowels look like they might break in a hard landing.
My solution was to build a quad in a waterproof, floating shell.