Fik Vening Meinesz (1887-1966) was a Dutch civil engineer, employed by the Dutch Geodetic Committee. He devised an apparatus, containing a system of multiple pendulums, with which he could measure gravity in areas where such measurements would otherwise be impossible. By chance, he was made aware that a submerged submarine, when powered by electromotors, would provide an ideal, sufficiently stable, platform for such measurements at sea. The Dutch Navy, in pursuit of good publicity in the interwar period, gave Vening Meinesz its full support, enabling him to carry out a number of submarine expeditions. His findings stimulated postwar geophysical and geological research, both in the USA and elsewhere. Initially Vening Meinesz used his results to validate the International Gravity Formula, being the closest mathematical representation of the equipotential surface of the Earth at sea level - the geoid. Subsequently he interpreted these results from a tectonophysical perspective, using them to explain the occurrence of the elongated 'Minus' zone of negative gravity anomalies, discovered by him to surround the Indonesian archipelago and which he postulated as being caused by a system of convection currents in the Earth's mantle. Whilst he supported the idea of fixed continents, becoming increasingly opposed to Wegener's idea of drifting continents, his work on mantle convection was to become fundamental to, and incorporated in, the hypothesis of seafloor spreading. This led to the current paradigm of plate tectonics, which interprets the 'Minus' zone as the expression of the boundary between two convergent plates.