Originally Posted by
mollusk
Really. Let the trailing "canoe" be huge and dragging an anchor. If Fr<1 (just like M<1 which I presume you are getting at) then the nature of the flow is elliptic in nature. Hence a trailing object can have an effect on the leading object.
That might be an interesting problem, but not the one I posed. Just like I didn't worry about the SS United States moving at 35 knots with a helicopter flying just behind.