Abstract: Disclosed herein is an exercise device which simulates the conditions of boardsailing and develops the particular body muscles used in boardsailing. The device has a curvilinear boom, a first tension line secured adjacent the extended ends of the boom, a tension transmission member adjustably secured to the first tension line intermediary of the ends thereof, a second line, one end of the second line being secured to the tension transmission member and the other end being adapted to be secured to an anchor member, and an adjustment plate carried by the second line for varying the distance between the tension transmission member and the anchor member.