Bill von Arx and Henry Stommel developed a powerful method of observing surface currents from a ship underway. The procedure relied on the electric potentials induced by the movement of the water through the earth's magnetic field. In this 1948 Atlantis Med cruise photo, the men in the foreground (from left, James Hollis, Gene Krance, Dean Bumpus, and Hans Cook) watch the readout from the geoelectromagnetokinetograph, known as the GEK (pronounced "geek"). Nat Corwin launches a mechanical Watson current meter aft, with Dave Owen photographing him.
(Photo by Don Fay, Woods Hole Oceanographic Institution)