A method and apparatus for sensing levels of insoluble fluids within a storage vessel utilizing an array of main capacitive sensors having differing geometries. The array of main capacitive sensors gives the ability to measure the levels of insoluble liquids in a vessel. Each of the main capacitive sensors include at least one pair of conductive plates capable of submersion in the at least two insoluble fluids, and the geometries of the pair of conductive plates differ and are distinct, such as in distance or in width, in each of the main capacitive sensors. In addition, the apparatus and method may include at least one reference sensor placed intermittently along the height of the vessel to provide input as to the permittivities of the insoluble fluids.