Rules World Sailing Case Book
World Sailing Cases
No sail shall be sheeted over or through any device that exerts outward pressure on a sheet or clew of a sail at a point from which, with the boat upright, a vertical line would fall outside the hull or deck, except:
  1. a headsail clew may be connected (as defined in Equipment Rules Of Sailing ) to a whisker pole, provided that a spinnaker is not set;
  2. any sail may be sheeted to or led above a boom that is regularly used for a sail and is permanently attached to the mast from which the head of the sail is set;
  3. a headsail may be sheeted to its own boom that requires no adjustment when tacking; and
  4. the boom of a sail may be sheeted to a bumkin.