A potable water producing system for disposition at a salt water body and methods of producing potable water are provided. The system includes a wave energy conversion system (AWECS) and a portable filtration system. The AWECS forms a floating articulated barge having an onboard desalination system including reverse osmosis membranes. The filtration system is a sand filter residing on a damping plate submerged in the salt water body and filters the adjacent salt water for providing filtered salt water to the onboard desalination system. Wave action on the articulated barge provides energy to pump and pressurize the filtered salt water from the sand filter to the reverse osmosis membranes to produce potable water. The wave action on the articulated barge effects shaking of the reverse osmosis membranes, thereby rendering them self-cleaning. The potable water can be used for various applications, e.g., bottling, replenishing aquifers, ground and/or aquifer remediation, irrigation, etc.