An improved personal propulsion device that generally imparts thrust directly to the user. The device allows hands free control of thrust magnitude and direction so both hands can grasp and control bicycle handlebars and brakes, watercraft paddles, ski poles or other apparatuses. The device is adjustable vertically, on the users' back, higher to allow sitting in a canoe or wheelchair and lower for standing on skates, skis, kick scooters etc. In one embodiment, the device includes an air compressor that is operatively connected to a cam mechanism engaged with the propulsion mechanism to provide compressed air. In another embodiment, the device includes a gap control mechanism to reduce or increase the size of the air inlet gap between the lip of the propeller shroud and an air horn to decrease noise levels or increase propulsion. The air horn can be gradiently flexible and warpable to allow controlled movement thereof.