Abstract: An underwater signaling device being removably mounted to the strap commonly found in scuba diving tanks. The device includes two elongated members an one of them being removably secured to the strap while the other one, hingedly mounted to the first one, is urged towards the latter by the spring action of the wound common ends connecting each other. A solid mass is rigidly mounted to the movable elongated member and an impact receiving plate is mounted to the fixed elongated member so that when the movable member is released the impact is taken by the plate and not directly by the tank.