it cant
a sail boat can go twice the speed of the wind in optimal conditions. speedboat 30-40
It depends on the speed of the vessel, the wind speed, the place and how choppy it is.
4x wind speed is so far the best alleged possible.
A sailing boat can not sail directly upwind, sail at about 45 degrees to the wind and tack (turn the boat through the wind) to the other side of the wind and continue in this zig-zag manner up wind.
A boat can sail into the wind by sailing backwards and forwards (tacking) at an angle to the wind and so making her way up.
The fastest point of sail is typically downwind with the wind directly behind the boat, known as sailing "dead downwind." To optimize speed in this position, sailors can use techniques such as adjusting sail trim, using spinnaker sails, and steering a straight course to catch the most wind and maximize boat speed.
Wind!
A sail is a piece of fabric attached to a boat, causing the wind to drive the boat along.
To sail against the wind, a boat has to 'tack'. This means that instead of sailing straight into the wind (which would get you nowhere) you sail in a zig-zag in the direction you intend to go. On each tack, the wind is on a different side of the sail.
a boat a sail and the wind
the force is there and it is easier to row
This will depend on a couple different things: ~boat ~wind pressure ~type of sails they can all change how fast the boat is going and in which direction