Case has been amended so that a boat may use tactics that interfere with or hinder another boat only if there is a reasonable chance of her tactics benefiting her final ranking in the event. Marginal markings indicate those paragraphs in which wording has changed.
Three new cases, Cases , and , have been added to The Case Book this year. Each of them is based on action taken at the World Sailing Annual Conference in November 2017.
Note: One more new case, Case 144, is still under consideration. It was approved in November 2017 subject to editing and then a vote by the World Sailing Racing Rules Committee (RRC) to approve the edited case. If editing of this case is completed and the case is approved by the RRC, a revised version of this supplement, including that case, will be issued.