Cal 20 hull layup

I was out sailing on the Cal 20 last night, and on one tack the sunlight angled into the cabin just right to show what appears to be an extra layer of roving in the layup, forward of the athwartships beam for the mast step. It would make sense to do that because it's where the hull gets smacked most by seas, and it would prevent oil-canning. Does anybody know if that was the plan? Chris Campbell