Patent ID: 7984685

Claim:
Apparatus for changing the attitude of an object immersed in a surrounding fluid comprising a first expandable reservoir, a second, separate expandable reservoir, the second expandable reservoir contained within a fixed volume of a static flotation shell, the shell being initially flooded with surrounding fluid to provide initial static flotation of the object having a passively stable orientation and having an initial center of mass and buoyancy and a net neutral buoyancy, a flexible conduit for transferring a ballast fluid which is greater in density than the surrounding fluid between the first and second reservoirs, the first and second reservoirs and the flexible conduit containing only a fixed quantity of the ballast fluid, a pump mechanism for controllably transferring the ballast fluid between the first and second reservoirs via the flexible conduit to provide another passively stable orientation of the object with a new center of mass and buoyancy but with an unchanged net neutral buoyancy, thereby controllably changing the attitude of the immersed object.