What is a Shellevator and how does it work?

A Shellevator™ is a pneumatically controlled shellfish aquaculture apparatus and method for growing shellfish. Compressed air automates vertical transport of containerized shellfish from the sea floor to above the sea surface. The invention consists of a frame with a top and bottom side, two or more air lift tanks are attached to the bottom side of the frame and one or more containers holding shellfish connected to the top side of the frame. A compressed air source supplies air through a manifold and air hoses connected to air lift tanks below a frame. Ascent is controlled by introducing compressed air through air supply lines and displacing water through an exhaust port at the bottom of the air lift tank(s) at one end (stern). The stern rests on the seafloor providing stability from inverting while the opposite end (bow) rises.  After most of the water is exhausted, the stern finally rises; this slanted orientation assures complete exhaust of water. The manifold valve(s) is closed when exhaust becomes air allowing the entire payload of oysters to emerge above the sea surface. Decent of the apparatus from the sea surface to the seafloor is accomplished by opening the manifold valves allowing the air to exhaust through the manifold. As water re-enters the lift tanks through the exhaust ports the stern sinks first providing stability and maximum air exhaust.  When floating, the tanks lift the frame and the containers out of the water to allow access and operations like air desiccation in order to prevent bio-fouling of the equipment and shellfish.