U Flag Rule
| Rules | World Sailing Case Book |
| Rule 30.3 U Flag Rule |
| If flag U has been displayed, no part of a boat's hull shall be in the triangle formed by the ends of the starting line and the first mark during the last minute before her starting signal. If a boat breaks this rule and is indentified, she shall be disqualified without a hearing, but not if the race is restarted or resailed. |