Originally Posted by smackdaddy
That said, I could also see what you're saying about the bow wanting to fall off...like a kayak in a river (which I actually have experienced).
So are there different dynamics at work here?
Yes there is.. the weight distribution in your average yacht is centered above the keel - and you have a deep keel and rudder adding their own lifting forces to keep the boat in line.
The weight distribution in a kayak is all down the stern - and you have a long, thin, keel with no appreciable lifting forces.
A yacht's rudder turns the boat around the axis of the keel, so, to get the "thought experiment" right, the proverbial finger should be placed in the center
of the boat - not the transom. ...but if you hold the rudder dead center in a current with the boat stationary, you'll find it will eventually fall off one way or another as soon as the keel's "lift force" (generated by the angle of attack to the average current flow direction) counteracts the rudder's smaller "lift force".
..all highly technical really.