When we sail at ‘high wind’, we travel – as far as possible – against the wind. The wind, thus, comes diagonally from the front. The propulsion takes place when the wind sweeps quickly past the sails, which are possibly set up in the middle of the boat. In contrast, if the boat travels ‘before the wind’; the sails are diagonal to the boat. The wind comes from behind, blows into the sails, and pushes the boat forwards.
