Seriously - US Sailing has the same kind of rules and camelbacks and such fall into such a category. I have one and live by it for long distance racing but for around the bouys I leave it in the trampoline bag. Race organizers should put an exception in the racing instructions to allow them and while I usually check with them ahead of time, I have yet to see a written exception.

I'm in the process of sewing on (figuring out how to) some heavy duty velcro and a nylon security strap so I can velcro my camel back to the back of my life vest so I can eliminate the additional straps around my torso (that could get entangled).