This self-potential dataset has been acquired at Makapuu/Kaiwi Coast (Oahu, Hawaii, USA)in the frame of a Summer Class entitled “Hydrogeophysics in Volcanic Environments” given at the University of Hawaii at Manoa. The data helps understanding and mapping underground water circulations in this study area.. Self Potential survey for ‘Ike Wai aim at understanding underground water circulations in the coastal area and across the High-Low divide (Big Island) as well as in valley/ridge systems and across the natural hydrogeological “dams” (O’ahu). The objective is to enhance our understanding of ground water flows and aquifer depths in the areas studied. Combined with other datasets (seismic noise and Electric Resistivity Tomography), the Self Potential method gives valuable structural and geological information (faults, lithological transitions/interfaces, etc). The self-potential is a difference of electrical potential naturally occurring in the ground, measured between two electrodes placed at the surface of the Earth or in boreholes.