Stable floating sounds challenging. A few magicians have done "walking on water" stunts over the years, and the general consensus is that they're doing it by h

Stable floating sounds challenging. A few magicians have done "walking on water" stunts over the years, and the general consensus is that they're doing it by having a sheet of plexiglass suspended just below the surface, somehow. Having it below the surface means the water surface ripples etc. are mostly unaffected. I'd find a relatively shallow lake, and hammer 4 wooden stakes into the lake bed (power tools for post-hammering exist), until the tops are just below the surface. You could start with longer-than-needed wooden stakes, hammer them in a bit, cut off the extra and then hammer the final distance. I suppose you could skip the plexiglass and put the chair legs directly onto the stakes, if they were positioned well enough.