To answer the question some have asked me out at our Lake
My interpretation is yes you are allowed to change rigs at the dg65 nationals from A+, to A, to B. (But only if you registered / measured them in at initial measuring before the contest started)
My Sources;
65 Nationals Sailing instructions at
6.3 While ashore or within a launching area boats may be adjusted, drained of water or repaired, have their sails/rigs changed or adjusted, have entangled objects removed, or have equipment repaired or changed.
REPLACEMENT OF EQUIPMENT In accordance with Class Rules A10, ......
DF65 Class Rules
A.10
Equipment Limitations Except in the case of demonstrable damage, only one hull, keel, ballast, rudder and one of each prescribed A+, A, B & C rig may be used per event.
Graham R