The typical American bathtub is a small tray, of the sort you'd wash your feet in before a dip in the local pool back during your verruca-plagued school days. Americans will respond that they do have proper bathtubs. This is a lie, those bathtubs only exist in movies and for the purposes of either murdering someone yourself or finding someone else's previous murderings, a sort of here's one I did earlier with a criminal flavour. Given the blimp-like proportions of The Average American, this means that maybe they can submerge a single buttock, if they use sufficient bubble bath to lubricate all the fubsy flesh into such a small volume of avocado bathroomware. Such minimized bathtubs could, of course, all be part of a devious plot to prevent the murderings. I would drown you, my dear, but the tub is terribly impractical, how about a boating trip?
American toilet bowls indeed have a depth and breadth that requires a lifeguard to be on hand in case you fall in. Also a water level usually high enough to be briefly flattering to any male who sits upon the watery throne. It doesn't help that any public toilet will feature cubicles mostly made out of gaps, rendering the process of bodily evacuation as a theatrical spectacle. Behold, the Great Backendio!