Abstract: Apparatus to stop the slapping of halyards against a mast includes a ring or other halyard encircling member lightly engagable with the halyard. A cleat or other line securing member is affixed to a shroud located outboard of the mast and halyards. A pulley or other line entraining means is affixed to the halyard above the line securing member. A line is tied to the ring entrained outward through the pulley and downward to the cleat where it is tied. Light tension in the line is sufficient to prevent halyard slap as a result of interruption of the resonance of the halyard.