Abstract: Buoyancy is controlled in a tethered object by pumping fluids, either of a first or second specific gravity, from an external source into either a first or second containment chamber to change the respective volumetric capacities of the first and second containment chambers. The containment chambers are configured such that the second chamber is at least partially enclosed within the first chamber. The second chamber is configured to expand and retract within the first chamber, which has a fixed housing. Expansion or contraction of the second chamber results in a corresponding inverse change in a volumetric capacity of the first chamber. The fluid chambers may be separate or contained within the same housing, and may be located on a towing vessel. Sensor data from the tethered object's environment may be used to control the transfer of fluid to the first and second chambers.

Abstract: The attitude of a submerged array of sensing elements can be changed using a fixed quantity of transferable ballast fluid having density different than water. In one embodiment, a non-rigid array of sensor elements is equipped with two expandable reservoirs connected between a flexible conduit which allows the ballast fluid to be transferred back and forth. Pumping fluid between the two reservoirs causes one reservoir to expand while the other contracts. Due to the density difference between the pumped fluid and water, the difference in volume between the two expandable reservoirs causes a shift in the center of buoyancy of the array system. The center of buoyancy in this way becomes offset from the center of gravity of the array system, causing a shift in the attitude of the array.

Abstract: The invention provides a means by which the attitude or orientation of a submerged object can be changed or altered using a fixed quantity of transferable ballast fluid which has a density less than that of the surrounding fluid in which the object is submerged. In one embodiment, the process utilizes a static negatively buoyant material (which could be a lead weight) to offset the net negative buoyancy of the transferable ballast fluid. In this way, the total overall buoyancy of the system does not change, but by transferring ballast fluid into expandable reservoirs which are physically separated from the static negatively buoyant material, the separation between the center of buoyancy and the center of mass of the object can be changed, and thus the attitude or orientation of the object, if it is unrestrained, may be changed.

Abstract: The system provides a means by which the attitude or orientation of a submerged object can be changed using a fixed quantity of transferable ballast fluid which has a density greater than that of the surrounding fluid in which the object is submerged. In one embodiment, the process utilizes a static flotation shell offset the net negative buoyancy of the transferable ballast fluid. In this way, the total overall buoyancy of the system does not change, but by transferring fluid into expandable reservoirs which are physically separated from the static flotation shell, the separation between the center of buoyancy and the center of mass of the object can be changed, and thus the attitude or orientation of the object, if it is unrestrained, may be changed.