rig tuning suggestions followup
 

Final answer to speed anomaly? Offset paddlewheel. Verified with GPS.
Just gonna have to learn to live with it. The rig has been tightened
according to the instructions referenced by a few responders and the
change in performance of the boat is to say the least, significant. It
is way more predictable on all points of sail. I can point way higher to
windward and the boat doesn't get squirrely on me. Thanks to all for the
tips.