The shape of the sails of before is essential. Indeed the jib or the genoa sail represents the leading edge of the whole of the profile of aerofoil which represents the foc/gv unit. It is in the part before EC unit that will constitute the major part of the bearing pressure which will give all the performance to the aerofoil. Always studied in its association with the large sail, the sails of before Racing DELTA are characterized by rather round attacks, advanced hollows in order to facilitate a navigation with variable angles of incidences.