Sail close to the wind

In its purely nautical sense, dating back to the 15th century, sailing close to the wind is a very fine line between rattling along at a good rate of knots and luffing the sails i.e. spilling the wind from the sails and being taken aback by going head on into the wind. From the 19th century, the expression has been used figuratively for taking a course of action fraught with risk.