http://www.xcontest.org/world/en/flights/detail:Weissenberger/27.10.2013/13:17

347 km

Previous record:
http://www.fai.org/fai-record-file/?recordId=14703

332.5 km, by George Stebbins.

Got pretty low after making the turnpoint and heading back.

There is some discrepancy about whether this is the record.