Pneumatically controlled aquaculture apparatus

A method of controlling floatation of an aquaculture apparatus, said method comprising the steps of:

• providing an aquaculture apparatus comprising:
• a lift vessel,
• a frame structure for holding shellfish therein, wherein the frame structure is attached to the lift vessel,
• a floatation control tank having a rigid tank wall, wherein the tank is attached to the frame structure in a generally centered position of the apparatus, wherein the tank is disposed above the lift vessel when the apparatus is in an upright position,
• a suspension buoy tethered to the apparatus,
• a compressed gas source configured to independently supply gas to each of the lift vessel and the tank, respectively,
• a lift vessel fluid supply line connecting the lift vessel to the compressed gas source, and
• a tank fluid supply line connecting the tank to the compressed gas source,
• wherein the lift vessel is configured to lift the frame structure to a position in which the frame structure is positioned entirely above a water surface when the apparatus is in a floating position on the water surface in which the lift vessel is filled with gas, wherein the tank is configured to suspend the frame structure in a first position below the water surface when the apparatus is in a first suspended position in which the tank is filled with gas and in which gas is evacuated from the lift vessel, and wherein the suspension buoy is configured to suspend the frame structure in a second position below the water surface when the apparatus is in a second suspended position in which the suspension buoy is floating on the water surface and gas is evacuated from both the tank and the lift vessel;
• submerging the apparatus in a body of water by evacuating gas from the lift vessel and from the tank, thereby allowing both the lift vessel and the tank to substantially fill with water;
• then supplying gas from the compressed gas source to the tank to substantially fill the tank with gas, thereby causing the tank to rise to the surface of the body of water with the lift vessel and the frame structure suspended in the body of water below the tank;
• and
• then floating the apparatus by supplying gas from the compressed gas source to the lift vessel, thereby causing the apparatus to float with the frame structure being held entirely above the surface of the water.