Flying an undeclared oversized jib as a spinnaker
Here''s the rule for spinnaker size, you can figure out whether a 170% would fit the measurements:
"a spinnaker width equal to 1.8 times J, a spinnaker height equal to .95 times the square root of I squared plus J squared"
If somehow this fits within the rules, it leaves open the question of why in hell would you do this as the perfomance would probably be horrendous, if the sail even fills...??