Skye:
This happens from prop wash and prop water pushing over the rudder. It not a real big deal, but you may want to inspect your rack and pinion gears under your seat. Take your wheel and with the seat open, and at the dock or anchor, work the wheel back and forth about 1/4+ turn in each direction. Watch the rack and the rudder post at the base to see if you have any real movement. I doubt that you will. If you see the bearing on the bottom loose or the rack loose then these could be the issue, but I have never heard of that. It most likely is prop water over the rudder.
Does it vibrate much when sailing? Ours will but only at 7-8 knots high speeds.
Hayden
