Through the 1950s and early 1960s, U.S. Naval survey ships, including United States Coast and Geodetic Survey ships engaged by the U.S. Navy, made major discoveries in Earth science. In 1955 for example, scientist aboard the USC&GS Pioneer (OSS 31) first observed the ocean floors magnetic striping while the ship towed the first marine magnetometer (developed at the University of California’s Scripps Oceanographic Research Institute) along the United State’s western coastal waters during the “Pioneer survey”. The discovery of magnetic stripping in combination with the discovery of the Mid-Atlantic Ridge’s seismologically active central valley was critical to the later development of the theory of plate tectonics.