In Transboundary Offshore Aquifers: A Search for a Governance Regime, Renee Martin-Nagle explains the geologic origins of offshore freshwater aquifers and proposes a governance regime for offshore aquifers that are shared by two or more nations. While the existence of freshwater offshore aquifers under continental shelves has been known for decades, none discovered thus far straddle an international border. In the event that an offshore aquifer shared by two or more nations is identified and targeted for development, selection of a governance regime for the aquifer will present a unique challenge, and several current legal systems could provide valuable guidance. While laws addressing transboundary land-based aquifers are still in a nascent stage, customary international law for surface water has evolved over centuries and could provide analogous rules for development of another freshwater resource. This monograph explores principles for sharing natural resources and proposes a governance regime for transboundary offshore aquifers.