They've closed a local footbridge near me and it's caused absolute havoc. I thought a ferry was a great solution, and was thinking of the 'grab the rope, walk along the deck' approach when someone pointed out how strong the current is and how hard it would be to hold onto. I came up with this as a solution (albeit less neat than their single angle rudder) and thought I was a genius. Both sad to see I'm not, and gratifying to see it would work :)