Abstract: A rescue signal device of this invention can be used on a life boat and on other objects for rescue, here more concerned about the use on a life boat. The device consists of a signal balloon which can float in the air high above the boat or object when the balloon is inflated with hydrogen in an emergency. The balloon used on a life boat is made of foldable, semi-transparent, red color and air proof material in cone shape having one end flat like a cut football. A circular board serving as a sail is attached to the flat end of the balloon. The balloon is linked to the life boat by several cables tied to the periphery of the circular board. Wind force acting on the face of the circular board gives power to sail the boat for saving the refugee's physical strength. The circular board can change the angle of attack of the wind by operating the cables to co-operate with rudder for proper heading of the boat.