an invisible line usually designated as between a pole with an orange flag on the Race Committee boat and a colored buoy that marks the line’s pin end. For a windward/leeward course, the start line is theoretically set perpendicular to the wind. For a distance race, the line is set perpendicular to the rhumb line. Several factors influence start line length: the number of competitors in the largest fleet, maximum boat length, maneuverability of the boats racing, wind velocity, wave height, and current drift and set. A start line may be set 0.1 nm or more leeward of the leeward mark to keep starters away from earlier section boats that may already be rounding the leeward mark. See also: box, favored end, and inner distance mark. Compare to: rabbit start.