Coast and Geodetic Survey Ship PIONEER III
engines, twin screw, length 311.6 feet, beam 41 feet, draft 13.8 feet.
Acquired from Navy in 1946, ex-MOBJACK, AGP-7, a seaplane tender.
In service 1946-1966 in Pacific Ocean. In August of 1955, this vessel
was equipped with a towed magnetometer developed by Victor Vacquier
of Scripps Institution of Oceanography while conducting surveys for
the Navy off the coast of California. Subsequent processing of the
magnetic data led to the discovery of magnetic striping on the seafloor,
a major discovery in the development of the Theory of Plate Tectonics.
This survey, from Point Conception to Cape Flattery became known as
“The Pioneer Survey.” The PIONEER also took part in the
International Indian Ocean Expedition in 1964 and was the first Coast
and Geodetic Survey vessel vessel to conduct operations in the Indian
Ocean. This vessel is commemorated by the naming of the geographic
feature Pioneer Fracture Zone.