Abstract
A physical model of a soft shell underwater float with an open bottom was constructed and the float was subjected to sinusoidal oscillation in the vertical direction in order to investigate the relations between the characteristic properties of the buoyancy and fluid forces in the movement of the float. No change in the fundamental period of the float was seen in response to the imposed oscillation, but there was a lag in the phase of the float response of up toone-quarter wavelength. Various fluid force factors approached values reported for a globular buoy as the float was increasingly filled with air, but hysteresis was very low. The drag coefficient showed much scatter. The dominant factor for control of vertical movement of a soft shell float with open bottom was buoyancy, not fluid resistance force. It was concluded that for the purposes of design and control of these systems, only the float volumetric capacity and air capacity must be considered.
