BOW-line, or Bowling, a rope fastened near the middle of the leech, or perpendicular edge of the square sails, by three or four subordinate parts called bridles. It is only used when the wind is so unfavourable that the sails must be all braced sideways, or close hauled to the wind: in this situation the bow-lines are employed to keep the weather or windward edges of the principal sails tight, forward, and steady, without which, they would always be shivering, and rendered incapable of service. To check the bow line is to slacken it, when the wind becomes large.