A raft drifting on the ocean is at the mercy of the elements. When a sailor describes this experience, one begins to understand the meaning of “in situ,” of being in touch with the water. The senses feel the wind, waves, rain, humidity, and temperature and recognize the change in the patterns of swell, clouds, flying fish, and sea birds. Thor Heyerdahl (1950) described these events vividly as he and five companions crossed 7,700 kilometers of the equatorial Pacific on Kon-Tiki in 1947. Detractors predicted that they would be lost at sea. It is of interest to investigate modern, in situ, and satellite ocean measurements to determine why and how the voyage succeeded.