also with monohulls, i think you can get the same effect by making the hull really long and skinny instead of splitting it in two? like water is not really compressible or as easy to displace so you would have something like what is called the area rule at supersonic and it gets more complex? cross sectional area becomes the main factor for drag above the speed of sound. also surface area. area is a square, volume is a cube. splitting volume increases surface area which would mean more drag... i dunno the whole story, i am not an engineer. this is an oblique wing plane, where the wings angle so that the cross sectional area is reduced, they go back to perpendicular for subsonic and swing around for supersonic. really weird. i do not fully understand it all...
Canada