Last time I was out sailing my Adventure I noticed a sound coming from the aft every time I had my left pedal at approximately three-quarters stroke of full travel. It sounded like the rudder cable tubs hitting the left side built-in pole holder. I tried constantly adjusting the rudder at the same pedal position and no sound.
Wind was light, protected waters, twenty pounds of gear and me 200 lbs.
My guess would me the hull was flexing, is this a problem or not?
If you need to see it I am just north of you on the other side of the base at Dana Point.
See ya on the water,