Typically wind is very cheaper than any fuel. Import/Export is the basic need of every country which is usually done through sea where there is a large wind potential. Sky Sail is a new emerging technology by virtue of which the ship is towed by a sail. The Sky Sail System is used parallel to and for relief of the main engine, if wind conditions allow. The main engine''s propulsion power remains fully available if required. This dual propulsion solution offers the flexibility required to minimize operating costs. In this book aerodynamic calculations are done using a sky sail whose dimensions are found from historical trend to calculate the fuel savings. Also break even points at different angle of attacks and different wind speeds for the same sky sail are also found. By using a Sky Sail System foresighted shipping companies now have the opportunity to increase their competitiveness and yields.