Abstract: A novel freely grasped hand-sail is described, which consists essentially of two profiled airfoil surfaces inclined towards each other at an angle between about 180.degree. and 120.degree., the leading edges of this hand-sail also forming an angle between about 180.degree. and 120.degree.. In one embodiment, the airfoil consists of sails kept rigid by aerodynamically preformed battens, which sails are stretched symmetrically between two masts and a middle boom. The freely grasped sail turns around its horizontal axis when set against the wind, and stabilizes itself at a certain turn, whereby the section that is more vertically directed yields forward thrust forces, to propel, for example, a sailboard, and the section that is more horizontal in this position mainly yields upward thrust forces to compensate the weight of the hand-sail and the rolling moment exerted on the sail. Wave-jumping while wind-surfing, in particular, can be made easier with the help of this hand-sail.