A structure described generally for altering one or more properties within a body of water includes a vessel configured to hold water. The vessel may have at least one wall. The at least one wall extends at least above a mean surface water level. At least one conduit extends downward from the holding vessel. The at least one conduit has a length that extends below the surface of the water. A propulsion system may be coupled to at least one of the vessel or the conduit and may be configured to provide forces to the vessel.