NOVELTY - The pump has a pump cylinder (7), including an open top and closed bottom (13), affixed on an open body of water. An inlet check valve (11) and an outlet check valve (12) are connected to openings on the cylinder. A ballast-weighted piston (8), disposed in the cylinder is connected to a buoy (1) via chain (4), is lifted up in response to wave action on the buoy and lowered by force of gravity to pump the fluid. Stop pins (6) limit upward stroke of the piston. Wear rings are mounted to the open top of the cylinder and to the top of the piston.    USE - Wave and tide actuated submersible pump for use in open body of water, such as seas, deep waters as well as shallower waters. Can be used in delivering water to hydroelectric power plant, providing contaminated fluid into evaporation ponds or large bodies of water for mineral and chemical extraction, refinement, and toxic waste removal, pumping salt water to be evaporated for forming moisture-laden clouds contributing to creation of new pasture and farmland, delivering salt water to desalination plant for extracting fresh water, delivering water to levied reservoir for hydroelectric power creation, pumping water out of the levied area for claiming land from sea, and delivering water to reservoir for raising sea animals and organisms for harvesting of sea animals and organisms (all claimed), as well as in seafood farming, oil and contaminant reclamation, and circulation of oxygen-rich water in dead area of sea.    ADVANTAGE - The pump utilizes the length of the pump cylinder and the depth of the sea or medium in which the pump is used to accommodate changing wave and tide conditions. The pump design is simple and yet robust enough to withstand most severe rigors of an oceanic environment, making the pump suited for shallower waters when embedded or in excavation of sufficient depth in fluid or ocean bed. When used in hydroelectric power generation, the pump contributes into making coastal states financially solvent and prosperous and lowering consumer energy bills as energy rationing is eliminated. The pump can serve as a power source for desalination operations, reducing energy consumption and operation costs while making desalination practical in fresh water-deprived regions. When used in seafood farming, the pumped sea water is used for raising fish or shrimp, eliminating need for shrimp and fish trawlers while guaranteeing full harvest.    DESCRIPTION OF DRAWING(S) - The drawing shows the cross sectional view of the pump mounted on the ocean bed or sea floor.    Buoy (1)    Chain (4)    Stop pins (6)    Pump cylinder (7)    Ballast-weighted piston (8)    Inlet check valve (11)    Outlet check valve (12)    Closed bottom (13)