...This competitor opened up his already ligthweight Zhik (CE Approved) jacket and removed more "bulk" floation, re-stitching with the white thread. Point was to make it less wind draggy...not so much to make it lighter. This was at a US National Tornado event. There were others at the event doing similar alterations.
I'm not passing judgement on this particular incident, but I would characterize that kind of action as: Intentionally breaking a rule for the purpose of gaining an unfair advantage or, more simply as: cheating.
Eric US SAILING Certified Judge Member, Area D Appeals Committee