Buoyancy Controlling Apparatus and Method

A buoyancy controlling apparatus for controlling buoyancy of a body to be submerged in a body of liquid, the buoyancy controlling apparatus including:

• a gas pressure vessel defining a pressure chamber for holding pressurized gas;
• a controllable buoyancy pressure vessel defining one or more internal chambers, said one or more internal chambers having an inlet leading into said one or more internal chambers and an outlet leading out of said one or more internal chambers;
• said one or more internal chambers being configured for holding pressurized gas and/or pressurized liquid introduced therein through the inlet of said one or more internal chambers;
• a pressure control valve in flow communication with said one or more internal chambers of the controllable buoyancy pressure vessel and with the pressure chamber of the gas pressure vessel, for controlling gas flow between the pressure chamber of the gas pressure vessel and said one or more internal chambers of the controllable buoyancy pressure vessel;
• a liquid pressurization device for pressurizing liquid, the liquid pressurization device including:
• (a) a pump having an inlet and an outlet for pumping pressurised liquid out of the pump and into said one or more internal chambers of the controllable buoyancy pressure vessel via the inlet thereof;
• (b) one or more valves in flow communication with the outlet of the pump for controlling fluid flow between the pump and the inlet of the controllable buoyancy pressure vessel for controlling fluid flow into said one or more internal chambers of the controllable buoyancy pressure vessel via the inlet thereof.