|dc.description.abstract||Over the past 20 years, underwater vehicle technology has undergone drastic improvements, and vehicles are quickly gaining popularity as a tool for numerous oceanographic tasks. Systems used on the vehicle to alter buoyancy, or variable buoyancy
(VB) systems, have seen only minor improvements during the same time period.
Though current VB systems are extremely robust, their lack of performance has become a hinderance to the advancement of vehicle capabilities.
This thesis first explores the current status of VB systems, then creates a model
of each system to determine performance. Second, in order to quantitatively compare
fundamentally different VB systems, two metrics, βm and βvol, are developed and
applied to current systems. By determining the ratio of performance to size, these
metrics give engineers a tool to aid VB system development. Finally, the fundamental
challenges in developing more advanced VB systems are explored, and a couple of
technologies are investigated for their potential use in new systems.||en_US||