Abstract: The invention relates generally to the stabilization of drifter buoys and the like and more particularly to surface or near surface Lagrangian Drifter Buoys launched from aircraft or surface vehicles and to an underwater suspension system adapted for stabilizing and maintaining the buoy at a predetermined depth in an upright position. The suspension assembly for use in combination with a buoy, having a generally elongated cylindrical hull, is comprised of two main components including 1) a collapsible longitudinal stabilizer means for providing horizontal drag and 2) a vertical stabilizer means suspended below and transverse the axis of the buoy. These two components act together to maintain the buoy in an upright position and to maintain it within the layer of water in which it is placed. The assembly is also compliant and as such the assembly has the ability to function for extended periods of time without the need for the use of inordinately strong or expensive materials.